Researcher Profile and Settings

Master

Affiliation (Master)

• Faculty of Engineering　Applied Chemistry　Inorganic Materials Chemistry

Affiliation (Master)

• Faculty of Engineering　Applied Chemistry　Inorganic Materials Chemistry

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Profile and Settings

Degree

• PhD（2007/12 Hokkaido University）

Profile and Settings

• Profile

  Dr. Akira Miura was born in Sapporo, Japan, in 1981. He received a Ph.D. in Engineering from Hokkaido University in 2007 and carried out postdoctoral research in the Department of Chemistry & Biochemistry at Cornell University and at the Institut für Anorganische Chemie at RTWH Aachen University in 2008–2010. After being appointed assistant professor at the Center for Crystal Science and Technology at Yamanashi University in 2010, he subsequently moved to the Faculty of Engineering at Hokkaido University in 2014. Dr. Miura’s research interests include the synthesis and characterization of oxides, hydroxides, oxynitrides, nitrides, sulfides and oxychalcogenides for use in novel semiconductors, catalysts, superconductors, and all-solid-state batteries.

• Name (Japanese)

  Akira

• Name (Kana)

  Miura

• Name

  201401080174757447

Alternate Names

https://www.eng.hokudai.ac.jp/labo/strchem/

Achievement

Research Interests

• 合成反応設計   Mixed-Anion Compounds   Nitride   Materials Chemistry   Analysis of Crystal Structure   Inorganic Synthesis Chemistry   

Research Areas

• Nanotechnology/Materials / Inorganic compounds/materials chemistry
• Nanotechnology/Materials / Inorganic materials

Research Experience

• 2021/10 - Today JSTさきがけ研究員（兼任）
• 2020/03 - 2025/03 Hokkaido University Faculty of Engineering Associate Professor
• 2016/04 - 2020/03 Hokkaido University Faculty of Engineering Assistant Professor
• 2019/09 - 2019/10 ローレンスバークレー国立研究所 客員研究員
• 2014/09 - 2016/03 Hokkaido University Faculty of Engineering Appointed Assistant Professor
• 2010/12 - 2014/08 University of Yamanashi Department of Research Interdisciplinary Graduate School of Medicine and Engineering Center for Crystal Science and Technology Assistant Professor
• 2010/02 - 2010/11 RTWH University (Prof. Richard Dronskowski) Research Fellow
• 2008/01 - 2009/12 Cornell University (Prof. Francis DiSalvo) Research Fellow

Education

• 2006/04 - 2007/12  Hokkaido University  Graduate School of Engineering  Engineering (PhD)
• 2004/04 - 2006/03  Hokkaido University  Graduate School of Engineering  Chemical Engineering (Master)
• 2000/04 - 2004/03  Hokkaido University  School of Engineering  Department of Applied Chemistry

Awards

• 2024/03 The Electrochemical Society of Japan IEEJ Distinguished Paper Award
   Electrocatalytic property of Zn-Al layered double hydroxides for CO2 electrochemical reduction 

  受賞者: Noboru Yamaguchi;Ryosuke Nakazato;Keeko Matsumoto;Masako Kakesu;Nataly Carolina Rosero-Navarro;Akira Miura;Kiyoharu Tadanaga
• 2023/07 東京工業大学フロンティア材料研究所 フロンティア材料研究所学術賞 研究奨励部門
   多元系セラミックス材料の高速合成法の開発とその理論解明 

  受賞者: 三浦章
• 2022/06 独立行政法人日本学術振興会先進セラミックス第一二四委員会 研究奨励賞
   新規窒化物創出を試行したNaNH2を用いた合成手法の開発 

  受賞者: 三浦章
• 2021/03 北海道大学大学院工学研究院 若手教員奨励賞授賞
   

  受賞者: 三浦 章
• 2020/12 日本化学会北海道支部 日本化学会北海道支部奨励賞
   硫化物および酸硫化物の合成手法開拓と機能性の発現 

  受賞者: 三浦章
• 2018/06 日本セラミックス協会 ２１世紀記念 倉田 元治賞
   

  受賞者: 三浦 章
• 2017/06 The Ceramic Society of Japan Progress Award
   Development of Synthesis Process of Nitrides and Oxynitrides 

  受賞者: Miura, Akira
• 2015/04 日本物理学会 Most Cited Articles in 2014 from Vol. 82 (2013)
  
• 2014/03 日本セラミックス協会 2014年年会最優秀ポスター発表賞
   

  受賞者: 三浦 章
• 2012/09 セラミックス協会第25回秋季シンポジウム 特定セッション優秀発表賞
   

  受賞者: 三浦 章
• 2012/01 50th Anniversary Symposium on Basic Science of Ceramics Presentation Award
   

  受賞者: Miura, Akira
• 2011/12 第6回日本フラックス成長研究発表会 発表賞
   

  受賞者: 三浦 章
• 2005/10 セラミックス協会東北北海道支部研究発表会 学生優秀発表賞
   

  受賞者: 三浦 章

Published Papers

• Robust Uniaxial Negative Thermal Expansion and Superconducting Properties in Co_1−xFe_xZr₃

  Hiroto Arima, Aichi Yamashita, Akira Miura, Hiroaki Ito, Chikako Moriyoshi, Hiroshi Fujihisa, Yoshikazu Mizuguchi

  Journal of the Physical Society of Japan 93 (12) 0031-9015 2024/12/15
• Stabilization and high thermoelectric performance of high-entropy-type cubic AgBi(S, Se, Te)2

  Asato Seshita, Aichi Yamashita, Takeshi Fujita, Takayoshi Katase, Akira Miura, Yuki Nakahira, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshikazu Mizuguchi

  Journal of Alloys and Compounds 1004 175679 - 175679 0925-8388 2024/11
• Inorganic-Organic Hybrid Sulfide Solid Electrolytes Based on the Tetraalkylammonium Iodide-LiI-Li₂S-P₂S₅ System

  Tong Fang, Kazuhiro Hikima, Hiroyuki Muto, Atsunori Matsuda, Yuta Fujii, Akira Miura, Kiyoharu Tadanaga

  Journal of The Electrochemical Society 0013-4651 2024/10/08 

  Abstract A series of novel inorganic-organic hybrid sulfide solid electrolytes were synthesized by doping Li₇P₂S₈I with a selection of tetraalkylammonium iodides, including tetramethylammonium iodide (TMAI), tetraethylammonium iodide (TEAI), tetrapropylammonium iodide (TPAI), and tetrabutylammonium iodide (TBAI). The electrolytes were prepared in varying compositions represented as (1-x) Li₇P₂S₈I ⸱ x (TMAI, TEAI, TPAI, TBAI), where x values were adjusted to 0, 0.05, 0.1, and 0.2 (molar ratio) to assess their influence on the electrolyte properties. These hybrids exhibited predominantly amorphous structures. Tetraalkylammonium iodides with longer alkyl chain length of the dopants showed lower ionic conductivity. Mechanical characterization via indentation tests indicated that the incorporation of longer alkyl chain length tetraalkylammonium iodides contributes to a reduction in the elastic modulus of the composites. This work underscores a methodological approach to modulate the structural and mechanical properties of sulfide solid electrolytes through strategic organic doping.
• Stress-Induced Martensitic Transformation in Na3YCl6

  Akira Miura, Koki Muraoka, Kotaro Maki, Saori Kawaguchi, Kazuhiro Hikima, Hiroyuki Muto, Atsunori Matsuda, Ichiro Yamane, Toshihiro Shimada, Hiroaki Ito, Yoshikazu Mizuguchi, Chikako Moriyoshi, Hiroshi Nakajima, Shigeo Mori, Hiroshi Oike, Akira Nakayama, Wenhao Sun, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  Journal of the American Chemical Society 146 (36) 25263 - 25269 0002-7863 2024/09/11 

  Martensitic transformation with volume expansion plays a crucial role in enhancing the mechanical properties of steel and partially stabilized zirconia. We believe that a similar concept could be applied to unexplored nonoxide materials. Herein, we report the stress-induced martensitic transformation of monoclinic Na3YCl6 with an ∼3.4% expansion. In situ synchrotron X-ray diffraction and atomistic simulations showed that anisotropic crystallographic transformation from monoclinic to rhombohedral Na3YCl6 occurs exclusively under uniaxial pressure; no effect is observed under hydrostatic pressure conditions. The uniaxially pressed powder compact of monoclinic Na3YCl6 showed a large indentation impression and low Young’s modulus, in contrast to its high bulk modulus, suggesting that these unique mechanical properties are induced by the martensitic transformation.
• Enhanced performance of graphene-incorporated electrodes for solid-state lithium-sulfur batteries through facilitated ionic diffusion pathways

  Abdulkadir Kızılaslan, Çağrı Gökhan Türk, Akira Miura, Kiyoharu Tadanaga

  Chemical Engineering Journal Elsevier BV 496 153588 - 153588 1385-8947 2024/09 [Not invited]
  
• Synthesis of ZrN–SiO₂ core–shell particles by a sol–gel process and use as particle‐based structured coloring material

  Shinji Noguchi, Akira Miura, Kiyoharu Tadanaga

  Journal of the American Ceramic Society 0002-7820 2024/07 

  Abstract ZrN–SiO₂ core–shell particles were prepared, where the ZrN core nanoparticles and SiO₂ shell were designed to exhibit localized surface plasmon resonances (LSPRs) and structural coloring. The heating of ZrO₂ nanoparticles with Mg₃N₂ under a nitrogen gas flow produced ZrN nanoparticles with a diameter in the range of 10–20 nm. The dispersion of ZrN nanoparticles in water exhibited an absorption maximum at approximately 700 nm owing to LSPRs. An SiO₂ shell was formed on the ZrN nanoparticles using a sol–gel process. Scanning transmission electron microscopy confirmed the formation of ZrN–SiO₂ core–shell particles containing ZrN particles with a diameter of approximately 10 nm. The SiO₂ shell thickness was controlled by varying the reaction time to form SiO₂. The use of particles as a structural component of a structural color material owing to the high uniformity of the size of obtained core–shell particles was investigated. The obtained ZrN–SiO₂ core–shell particles were arrayed on a glass substrate using a layer‐by‐layer method. The particle‐stacked film of the ZrN–SiO₂ core–shell particles exhibited the maximum reflection depending on the particle size of the SiO₂ shell.
• Preparation of TaON thin films by nitridation of solution process-derived precursor films with urea

  Amon Higuchi, Nataly Carolina Rosero-Navarro, Akira Miura, Yuji Masubuchi, Kiyoharu Tadanaga

  Journal of Sol-Gel Science and Technology 0928-0707 2024/06/27
• Surface modification of Li3PO4 to Li1.3Al0.3Ti1.7(PO4)3 by wet chemical process and its sintering behavior

  Kento Ishii, Yuri Taniguchi, Akira Miura, Shogo Miyoshi, Kazunori Takada, Go Kawamura, Hiroyuki Muto, Atsunori Matsuda, Masayoshi Fuji, Tetsuo Uchikoshi

  Journal of the Ceramic Society of Japan 132 (6) 257 - 266 1882-0743 2024/06 

  The surface modification of lithium phosphate on lithium alumina titanium phosphate (LATP) by a wet chemical method densified the LATP to over 90 % at a sintering temperature of 800 °C. This temperature was approximately 300 °C lower than that of LATP without additives. Densification of LATP with lithium phosphate significantly progressed from 700 to 800 °C, and endothermic peaks corresponding to its melting were found in a similar temperature range, suggesting that the densification mechanism would be due to liquid phase sintering. The liquid phase of Li3PO4 is produced by a multi-step thermal decomposition involving the reaction with LATP. The sintered LATP with lithium phosphate showed a density of about 90 % and the highest ionic conductivity of 3.5 © 1014 S/cm at 25 °C, suggesting an excellent Li ion conducting, solid electrolyte material.
• Structural Color Materials with Color Mixing Effect Using Noble Metal-Free Plasmonic Particles in SiO₂-ZrN System

  Akira Miura

  Advanced Optical Materials 2400287  2024/04/15 [Refereed]
  
• Nitrogen-Rich Molybdenum Nitride Synthesized in a Crucible under Air

  Momoka Demura, Masanori Nagao, Chul-Ho Lee, Yosuke Goto, Yusuke Nambu, Maxim Avdeev, Yuji Masubuchi, Takato Mitsudome, Wenhao Sun, Kiyoharu Tadanaga, Akira Miura

  Inorganic Chemistry 63 (11) 4989 - 4996 0020-1669 2024/03/05
• Nickel Carbide Nanoparticle Catalyst for Selective Hydrogenation of Nitriles to Primary Amines

  Sho Yamaguchi, Daiki Kiyohira, Kohei Tada, Taiki Kawakami, Akira Miura, Takato Mitsudome, Tomoo Mizugaki

  Chemistry – A European Journal 30 (13) 0947-6539 2024/01/16 

  Abstract Despite its unique physicochemical properties, the catalytic application of nickel carbide (Ni₃C) in organic synthesis is rare. In this study, we report well‐defined nanocrystalline Ni₃C (nano‐Ni₃C) as a highly active catalyst for the selective hydrogenation of nitriles to primary amines. The activity of the aluminum‐oxide‐supported nano‐Ni₃C (nano‐Ni₃C/Al₂O₃) catalyst surpasses that of Ni nanoparticles. Various aromatic and aliphatic nitriles and dinitriles were successfully converted to the corresponding primary amines under mild conditions (1 bar H₂ pressure). Furthermore, the nano‐Ni₃C/Al₂O₃ catalyst was reusable and applicable to gram‐scale experiments. Density functional theory calculations suggest the formation of polar hydrogen species on the nano‐Ni₃C surface, which were attributed to the high activity of nano‐Ni₃C towards nitrile hydrogenation. This study demonstrates the utility of metal carbides as a new class of catalysts for liquid‐phase organic reactions.
• Low-Temperature Chiral Crystal Structure and Superconductivity in (Pt0.2Ir0.8)3Zr5

  Yuto Watanabe, Hiroto Arima, Aichi Yamashita, Akira Miura, Chikako Moriyoshi, Yosuke Goto, Chul Ho Lee, Ryuji Higashinaka, Hidetomo Usui, Shogo Kawaguchi, Kazuhisa Hoshi, Yoshikazu Mizuguchi

  Journal of the American Chemical Society 146 (1) 773 - 781 0002-7863 2024/01/10 

  We report the observation of superconductivity in (Pt0.2Ir0.8)3Zr5 with a chiral space group (P6122) at low temperatures. The bulk nature of the superconductivity at a transition temperature of 2.2 K was confirmed using specific heat measurements. We revealed that (Pt0.2Ir0.8)3Zr5 obeys the weak-coupling Bardeen-Cooper-Schrieffer model, and the dominant mechanism in the upper critical field is the orbital pair-breaking limit rather than the Pauli-Clogston limit. This indicates that the antisymmetric spin-orbit coupling caused by the chiral crystal structure does not significantly affect the superconductivity of (Pt0.2Ir0.8)3Zr5
• Synthesis, electronic structure, and redox chemistry of Li₂MnP₂S₆, a candidate high-voltage cathode material

  Akira Miura

  ChemRxiv 2024
• Superconducting properties and electronic structure of CuAl₂-type transition-metal zirconide Fe_1-xNi_xZr₂

  Akira Miura

  ArXiv 2024
• Preparation of phenylsilsesquioxane thick films using thermal softening behavior

  Akira Miura

  Journal of Sol-Gel Science and Technology 2024
• Electrochemical nitrogen reduction reaction to ammonia using perovskite-type oxynitrides BaMO₂N (M = Nb, Ta) and enhancement of the activity by acid treatment

  Akira Miura

  ChemRxiv 2024
• Carbon-Free Cathode Materials Based on Titanium Compounds for Zn-Oxygen Aqueous Batteries

  Akira Miura

  Batteries 2024
• High-pressure phase and pressure-induced phase transition of Ag₃YCl₆

  Kotaro Maki, Koki Muraoka, Saori Kawaguchi, Taku Tanimoto, Akira Nakayama, Seiya Yokokura, Toshihiro Shimada, Kiyoharu Tadanaga, Akira Miura

  CrystEngComm 26 (13) 1814 - 1818 2024 

  Hexagonal Ag₃YCl₆ was found to transform into a monoclinic structure above ∼1.5 GPa.
• Solution plasma assisted Mn-doping: a novel strategy for developing highly durable and active oxygen evolution catalysts

  Akira Miura

  Sustainable Energy & Fuels 8 789 - 796 2024 [Refereed]
  
• Preparation of carbon-sulphur composite electrodes by solution impregnation and application to all-solid-state lithium-sulphur batteries

  Akira Miura

  Energy Advances 2024/01 [Refereed][Not invited]
  
• Observation of superconductivity and enhanced upper critical field of η-carbide-type oxide Zr4Pd2O

  Yuto Watanabe, Akira Miura, Chikako Moriyoshi, Aichi Yamashita, Yoshikazu Mizuguchi

  Scientific Reports 13 (1) 2023/12 

  We report the first observation of bulk superconductivity of a η-carbide-type oxide Zr4Pd2O. The crystal structure and the superconducting properties were studied through synchrotron X-ray diffraction, magnetization, electrical resistivity, and specific heat measurement. The superconducting transition was observed at T c = 2.73 K. Our measurement revealed that the η-carbide-type oxide superconductor Zr4Pd2O shows an enhanced upper critical field μ 0 H c2(0) = 6.72 T, which violates the Pauli-Clogston limit μ 0 H P = 5.29 T. On the other hand, we found that the enhanced upper critical field is absent in a Rh analogue Zr4Rh2O. The large μ 0 H c2(0) of Zr4Pd2O would be raised from strong spin–orbit coupling with Pd-4d electrons. The discovery of new superconducting properties for Zr4Pd2O would shed light on the further development of η-carbide-type oxide superconductors.
• Absence of T_c-Pinning Phenomenon under High Pressure in High-Entropy REO_0.5F_0.5BiS₂ Layered Superconductor

  Yoshikazu Mizuguchi, Kazuki Yamane, Ryo Matsumoto, Kazuhisa Hoshi, Aichi Yamashita, Akira Miura, Yuki Nakahira, Hirokazu Kadobayashi, Saori I. Kawaguchi, Yoshihiko Takano

  Journal of the Physical Society of Japan 92 (11) 0031-9015 2023/11/15
• Stability and Metastability of Li3YCl6 and Li3HoCl6

  Hiroaki Ito, Yuki Nakahira, Naoki Ishimatsu, Yosuke Goto, Aichi Yamashita, Yoshikazu Mizuguchi, Chikako Moriyoshi, Takashi Toyao, Ken-ichi Shimizu, Hiroshi Oike, Masanori Enoki, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  Bulletin of the Chemical Society of Japan 96 (11) 1262 - 1268 0009-2673 2023/11/15 [Refereed][Not invited]
  
• Fe Site Order and Magnetic Properties of Fe_1/4NbS₂

  Erick A. Lawrence, Xudong Huai, Dongwook Kim, Maxim Avdeev, Yu Chen, Grigorii Skorupskii, Akira Miura, Austin Ferrenti, Moritz Waibel, Shogo Kawaguchi, Nicholas Ng, Bobby Kaman, Zijian Cai, Leslie Schoop, Satya Kushwaha, Feng Liu, Thao T. Tran, Huiwen Ji

  Inorganic Chemistry 62 (44) 18179 - 18188 0020-1669 2023/10/20
• Electrocatalytic property of Zn-Al layered double hydroxides for CO2 electrochemical reduction

  Noboru Yamaguchi, Ryosuke Nakazato, Keeko Matsumoto, Masako Kakesu, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  JOURNAL OF ASIAN CERAMIC SOCIETIES 11 (3) 406 - 411 2187-0764 2023/07 

  Electrocatalytic CO2 reduction reaction (CO2RR) has attracted considerable attention as a technology to recycle carbon dioxide (CO2) into raw materials for chemicals using renewable energies. In this study, the electrocatalytic CO2RR activity of Zn-Al layered double hydroxides (LDHs) was studied. Zn-Al LDHs loaded carbon sheets were prepared, and CO2 RR was performed using CO2-saturated KHCO3 electrolyte to confirm the catalytic ability of Zn-Al LDH. Zn-Al LDHs intercalated with CO32- anion were synthesized using the mixture of metal nitrates with the different molar ratio of Zn2+/Al3+ by the co-precipitation process, whose corresponding products were named as Zn2Al1 LDH, Zn3Al1 LDH, and Zn4Al1 LDH, respectively. Except for Zn2Al1 LDH, ZnO was observed to exist as an impurity. The synthesized Zn-Al LDHs exhibited the electrocatalytic CO2RR activity for CO formation. In the case of the Zn2Al1 LDH, the current density of 15 mA cm(-2) was obtained with 77% selectivity for CO and 94% selectivity for (CO + H-2) at - 1.4 V vs. RHE. Furthermore, Zn3Al1 and Zn4Al1 LDHs showed a significant change relating to ZnO impurities in the XRD patterns and SEM images before and after the CO2RR whereas Zn2Al1 LDH did not show it. These results indicate that Zn-Al LDH is promising as a CO2RR electrocatalyst for CO formation.
• Effects of equivalent composition on superconducting properties of high-entropy REOBiS2 (RE = La, Ce, Pr, Nd, Sm, Gd) single crystals

  Yuma Fujita, Masanori Nagao, Akira Miura, Daisuke Urushihara, Yoshikazu Mizuguchi, Yuki Maruyama, Satoshi Watauchi, Yoshihiko Takano, Isao Tanaka

  Physica C: Superconductivity and its Applications 608 1354254 - 1354254 0921-4534 2023/05
• Thermoelectric Properties of Zintl Arsenide EuCuAs

  Akira Miura

  Journal of Electronic Materials 52 (5) 3121 - 3131 0361-5235 2023/05
• Synthesis and Characterization of a Trigonal Layered Compound AgInS2

  Akira Miura

  ACS Omega 8 (12) 11288 - 11292 2470-1343 2023/03/28 [Refereed]
  
• Glassy atomic vibrations and blurry electronic structures created by local structural disorders in high-entropy metal telluride superconductors

  Yoshikazu Mizuguchi, Hidetomo Usui, Rei Kurita, Kyohei Takae, Md Riad Kasem, Ryo Matsumoto, Kazuki Yamane, Yoshihiko Takano, Yuki Nakahira, Aichi Yamashita, Yosuke Goto, Akira Miura, Chikako Moriyoshi

  Materials Today Physics 32 101019 - 101019 2542-5293 2023/03 [Refereed][Not invited]
  
• Uniaxial Negative Thermal Expansion in an Orthorhombic Superconductor CoZr₃

  Hiroto Arima, Tatsuki Inui, Aichi Yamashita, Akira Miura, Hiroaki Itou, Chikako Moriyoshi, Hiroshi Fujihisa, Yoshikazu Mizuguchi

  Journal of the Physical Society of Japan 92 (2) 0031-9015 2023/02/15 [Refereed][Not invited]
  
• Microwave assisted preparation of LiFePO4/C coated LiMn1.6Ni0.4O4 for Li-ion batteries with superior electrochemical properties

  F.A. Vásquez, N.C. Rosero-Navarro, R. Jalem, A. Miura, Y. Goto, Y. Tateyama, J.A. Calderón, K. Tadanaga

  Applied Materials Today 30 101697 - 101697 2352-9407 2023/02 [Refereed]
  
• Synthesis of manganese nitride doped with rare-earth elements and their oxygen reduction reaction activity

  Hayato Sakai, Shigeto Hirai, Masanori Nagao, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  Journal of Alloys and Compounds 935 167986 - 167986 0925-8388 2023/02
• Estimation of Grüneisen Parameter of Layered Superconductor LaO0.5F0.5BiS2-xSex (x = 0.2,0.4,0.6,0.8,1.0)

  Fysol Ibna Abbas, Kazuhisa Hoshi, Yuki Nakahira, Miku Yoshida, Aichi Yamashita, Hiroaki Ito, Akira Miura, Chikako Moriyoshi, Chul-Ho Lee, Yoshikazu Mizuguchi

  Journal of the Physical Society of Japan 92 (1) 0031-9015 2023/01/15 [Refereed][Not invited]
  
• Intercalation on Transition Metal Trichalcogenides via a Quasi‐Amorphous Phase with 1D Order

  Masaya Fujioka, Melbert Jeem, Kento Sato, Masashi Tanaka, Kazuki Morita, Taizo Shibuya, Kiyonori Takahashi, Suguru Iwasaki, Akira Miura, Masanori Nagao, Satoshi Demura, Hideaki Sakata, Madoka Ono, Hideo Kaiju, Junji Nishii

  Advanced Functional Materials 33 (10) 2208702 - 2208702 1616-301X 2023/01/07 [Refereed]
   

  Abstract Intercalation into 1D transition metal trichalcogenides (TMTs) in which fibers are bonded by a weak van der Waals force can be expected to create various intercalation compounds and develop unique physical properties according to the combination of the host materials and guest ions. However, structural changes via intercalation into 1D TMTs are not as simple as those in 2D transition metal dichalcogenides (TMDs) and are still not understood comprehensively. ZrTe₃: a typical compound with a 1D trigonal prismatic structure, belongs to TMTs. Herein, through the Ag introduction to ZrTe₃ via solid‐state intercalation, a novel crystal phase with a 1D octahedral structure and a quasi‐amorphous (QA) phase during the structural transition are discovered; the QA phase is a novel state of matter in which long‐range order is lost while retaining 1D order. Based on the Ag concentration, the transport properties are flexibly modulated from superconductivity to semiconductivity. Density functional theory calculations indicate the attraction between Ag ions and the pair diffusion due to their attraction. Furthermore, judging the attraction or repulsion between guest ions predicts whether to induce a QA phase or simple lattice expansion like the intercalation into 2D TMDs.
• Inorganic–organic hybrid solid electrolytes in the tetramethylammonium iodide–LiI–Li₂S–P₂S₅ system for all-solid-state lithium batteries

  Tong Fang, Hikaru Tokiwa, Akira Miura, Kiyoharu Tadanaga

  Sustainable Energy & Fuels 7 (17) 4297 - 4302 2023 

  A new type of glassy solid electrolyte was prepared by doping tetramethylammonium iodide (TMAI) in Li₇P₂S₈I. TMAI can suppress the large volume change of a Si electrode during cycling.
• CO2 Electrochemical Reduction with Zn-Al Layered Double Hydroxide-Loaded Gas-Diffusion Electrode

  Ryosuke Nakazato, Keeko Matsumoto, Noboru Yamaguchi, Margherita Cavallo, Valentina Crocellà, Francesca Bonino, Matthias Quintelier, Joke Hadermann, Nataly Carolina ROSERO Navarro, Akira Miura, Kiyoharu Tadanaga

  Electrochemistry 91 (9) 1344-3542 2023 

  Carbon dioxide electrochemical reduction (CO2ER) has attracted considerable attention as a technology to recycle CO2 into raw materials for chemicals using renewable energies. We recently found that Zn-Al layered double hydroxides (Zn-Al LDH) have the CO-forming CO2ER activity. However, the activity was only evaluated by using the liquid-phase CO2ER. In this study, Ni-Al and Ni-Fe LDHs as well as Zn-Al LDH were synthesized using a facile coprecipitation process and the gas-phase CO2ER with the LDH-loaded gas-diffusion electrode (GDE) was examined. The products were characterized by XRD, STEM-EDX, BF-TEM and ATR-IR spectroscopy. In the ATR-IR results, the interaction of CO2 with Zn-Al LDH showed a different b t l ti ith t t th LDH ti , different electrocatalytic activity. The LDH-loaded GDE was prepared by simple drop-casting of a catalyst ink onto carbon paper. For gas-phase CO2ER, only Zn-Al LDH exhibited the CO2ER activity for carbon monoxide (CO) formation. By using different potassium salt electrolytes affording neutral to strongly basic conditions, such as KCl, KHCO3 and KOH, the gas-phase CO2ER with Zn-Al LDH-loaded GDE showed 1.3 to 2.1 times higher partial current density for CO formation than the liquid-phase CO2ER.
• Synthesis of lithium oxy-thiophosphate solid electrolytes with Li₁₀GeP₂S₁₂ structure by a liquid phase process using 2-propanol

  Shunichiro Shiba, Akira Miura, Yuta Fujii, Kiyoharu Tadanaga, Kota Terai, Futoshi Utsuno, Hiroyuki Higuchi

  RSC Advances 13 (33) 22895 - 22900 2023 

  Crystal structure model of lithium oxy-thiophosphates (LPSO) prepared in the present study (a) and Li₁₀GeP₂S₁₂ (b). Purple spheres indicate P, yellow spheres indicate S, red spheres indicate O, and green spheres indicate Ge.
• Beneficial Effect of LiFePO4/C coating on Li0.9Mn1.6Ni0.4O4 obtained by microwave heating

  F.A. Vásquez, N.C. Rosero-Navarro, A. Miura, Y. Goto, K. Tadanaga, J.A. Calderón

  Electrochimica Acta 437 (1) 141544  2023/01 [Refereed]
  
• Two-step liquid-phase synthesis of argyrodite Li₆PS₅Cl solid electrolyte using nonionic surfactant

  Akira Miura

  Boletín de la Sociedad Española de Cerámica Y Vidrio 0366-3175 2023 [Refereed]
  
• Tuning of upper critical field in a vanadium-based A15 superconductor by the compositionally-complex-alloy concept

  Yuki Nakahira, Ryosuke Kiyama, Aichi Yamashita, Hiroaki Itou, Akira Miura, Chikako Moriyoshi, Yosuke Goto, Yoshikazu Mizuguchi

  Journal of Materials Science 57 (33) 15990 - 15998 0022-2461 2022/09
• Highly active and stable surface structure for oxygen evolution reaction originating from balanced dissolution and strong connectivity in BaIrO3 solid solutions

  Shigeto Hirai, Shunsuke Yagi, He Chan Oh, Yoshiki Sato, Wei Liu, En Pei Liu, Wei Tin Chen, Akira Miura, Masanori Nagao, Tomoya Ohno, Takeshi Matsuda

  RSC Advances 12 (37) 24427 - 24438 2022/08/26 [Refereed][Not invited]
   

  Catalysts for the oxygen evolution reaction (OER) are receiving great interest since OER remains the bottleneck of water electrolyzers for hydrogen production. Especially, OER in acidic solutions is crucial since it produces high current densities and avoids precipitation of carbonates. However, even the acid stable iridates undergo severe dissolution during the OER. BaIrO3 has the strongest IrO6 connectivity and stable surface structure, yet it suffers from lattice collapse after OER cycling, making it difficult to improve the OER durability. In the present study, we have successfully developed an OER catalyst with both high intrinsic activity and stability under acidic conditions by preventing the lattice collapse after repeated OER cycling. Specifically, we find that the substitution of Ir-site with Mn for BaIrO3 in combination with OER cycling leads to a remarkable activity enhancement by a factor of 28 and an overall improvement in stability. This dual enhancement of OER performance was accomplished by the novel strategy of slightly increasing the Ir-dissolution and balancing the elemental dissolution in BaIr1−xMnxO3 to reconstruct a rigid surface with BaIrO3-type structure. More importantly, the mass activity for BaIr0.8Mn0.2O3 reached ∼73 times of that for IrO2, making it a sustainable and promising OER catalyst for energy conversion technologies.
• Lattice Anharmonicity in BiS₂-Based Layered Superconductor RE(O,F)BiS₂ (RE = La, Ce, Pr, Nd)

  Fysol Ibna Abbas, Kazuhisa Hoshi, Aichi Yamashita, Yuki Nakahira, Yosuke Goto, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Kensei Terashima, Ryo Matsumoto, Yoshihiko Takano, Yoshikazu Mizuguchi

  Journal of the Physical Society of Japan 91 (7) 074706  0031-9015 2022/07/15 [Refereed]
  
• Impact of Sulfur Infiltration Time and Its Content in an N-doped Mesoporous Carbon for Application in Li-S Batteries

  Jennifer Laverde, Nataly C. Rosero-Navarro, Akira Miura, Robison Buitrago-Sierra, Kiyoharu Tadanaga, Diana López

  Batteries 8 (6) 58 - 58 2022/06/17 [Refereed][Not invited]
   

  Li-S batteries are ideal candidates to replace current lithium-ion batteries as next-generation energy storage systems thanks to their high specific capacity and theoretical energy density. Composite electrodes based on carbon microstructures are often used as a host for sulfur. However, sulfur lixiviation, insoluble species formation, and how to maximize the sulfur-carbon contact in looking for improved electrochemical performance are still major challenges. In this study, a nitrogen doped mesoporous carbon is used as a host for sulfur. The S/C composite electrodes are prepared by sulfur melting-diffusion process at 155 °C. The effect of the sulfur melting-diffusion time [sulfur infiltration time] (1–24 h) and sulfur content (10–70%) is investigated by using XRD, SEM, TEM and TGA analyses and correlated with the electrochemical performance in Li-S cells. S/C composite electrode with homogeneous sulfur distribution can be reached with 6 h of sulfur melting-diffusion and 10 wt.% of sulfur content. Li-S cell with this composite shows a high use of sulfur and sufficient electronic conductivity achieving an initial discharge capacity of 983 mA h g−1 and Coulombic efficiency of 99% after 100 cycles.
• Preparation of transparent and mechanically hard inorganic-organic hybrid thick films from 3-glycidoxypropyltrimethoxysilane and zirconium propoxide

  Takuto Toide, Nataly Carolina Rosero-Navarro, Akira Miura, Hiromitsu Kozuka, Kiyoharu Tadanaga

  Journal of Sol-Gel Science and Technology 104 (3) 478 - 483 0928-0707 2022/05/20 [Refereed][Not invited]
  
• Investigation of superconductivity in Ce-doped (La,Pr)OBiS₂ single crystals

  Akira Miura

  ArXiv 15 (9) 2977 - 2977 2022/04/19 [Refereed]
   

  Single crystals of Ce-doped (La,Pr)OBiS2 superconductors, the multinary rare-earth elements substituted ROBiS2, were successfully grown. The grown crystals typically had a size of 1–2 mm and a plate-like shape with a well-developed c-plane. The c-axis lattice constants of the obtained (La,Ce,Pr)OBiS2 single crystals were approximately 13.6–13.7 Å, and the superconducting transition temperature was 1.23–2.18 K. Valence fluctuations of Ce and Pr were detected through X-ray absorption spectroscopy analysis. In contrast to (Ce,Pr)OBiS2 and (La,Ce)OBiS2, the superconducting transition temperature of (La,Ce,Pr)OBiS2 increased with the increasing concentrations of the tetravalent state at the R-site.
• Estimation of the Grüneisen Parameter of High-Entropy Alloy-Type Functional Materials: The Cases of REO0.7F0.3BiS2 and MTe

  Fysol Ibna Abbas, Yuki Nakahira, Aichi Yamashita, Md. Riad Kasem, Miku Yoshida, Yosuke Goto, Akira Miura, Kensei Terashima, Ryo Matsumoto, Yoshihiko Takano, Chikako Moriyoshi, Yoshikazu Mizuguchi

  Condensed Matter 7 (2) 34 - 34 2410-3896 2022/04/18 [Refereed]
   

  In functional materials such as thermoelectric materials and superconductors, the interplay between functionality, electronic structure, and phonon characteristics is one of the key factors to improve functionality and to understand the underlying mechanisms. In the first part of this article, we briefly review investigations on lattice anharmonicity in functional materials on the basis of the Grüneisen parameter (γG). We show that γG can be a good index for large lattice anharmonicity and for detecting a change in anharmonicity amplitude in functional materials. Then, we show original results on the estimation of γG for recently developed high-entropy alloy-type (HEA-type) functional materials with a layered structure and a NaCl-type structure. As a common trend for those two systems with two- and three-dimensional structures, we found that γG increased with a slight increase in the configurational entropy of mixing (ΔSmix) and then decreased with increasing ΔSmix in the high-entropy region.
• Synthesis and Characterization of High-Entropy-Alloy-Type Layered Telluride MBi₂Te₄ (M = Ag, In, Sn, Pb, Bi)

  Akira Miura

  Materials 15 (7) 2614 - 2614 2022/04/01 [Refereed]
   

  Recently, high-entropy alloys (HEAs) and HEA-type compounds have been extensively studied in the fields of material science and engineering. In this article, we report on the synthesis of a layered system MBi2Te4 where the M site possesses low-, middle-, and high-entropy states. The samples with M = Pb, Ag1/3Pb1/3Bi1/3, and Ag1/5In1/5Sn1/5Pb1/5Bi1/5 were newly synthesized and the crystal structure was examined by synchrotron X-ray diffraction and Rietveld refinement. We found that the M-Te2 distance was systematically compressed with decreasing lattice constants, where the configurational entropy of mixing at the M site is also systematically increased. The details of structural refinements and the electrical transport property are presented.
• Graphite/Li7P3S11 composite prepared by “seed” process for all-solid-state batteries

  Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga, Atsunori Matsuda

  Solid State Ionics 372 115789 - 115789 0167-2738 2021/12 [Refereed]
  
• Preparation of Composite Electrodes for All-Solid-State Batteries Based on Sulfide Electrolytes: An Electrochemical Point of View

  Sara Giraldo, Koki Nakagawa, Ferley A. Vásquez, Yuta Fujii, Yongming Wang, Akira Miura, Jorge A. Calderón, Nataly C. Rosero-Navarro, Kiyoharu Tadanaga

  Batteries 7 (4) 77 - 77 2021/11/11 [Refereed]
   

  All-solid-state batteries (ASSBs) are a promising response to the need for safety and high energy density of large-scale energy storage systems in challenging applications such as electric vehicles and grid integration. ASSBs based on sulfide solid electrolytes (SEs) have attracted much attention because of their high ionic conductivity and wide electrochemical windows of the sulfide SEs. Here, we study the electrochemical performance of ASSBs using composite electrodes prepared via two processes (simple mixture and solution processes) and varying the ionic conductor additive (80Li2S∙20P2S5 and argyrodite-type Li6PS5Cl). The composite electrodes consist of lithium-silicate-coated LiNi1/3Mn1/3Co1/3O2 (NMC), a sulfide SE, and carbon additives. The charge-transfer resistance at the interface of the solid electrolyte and NMC is the main parameter related to the ASSB’s status. This value decreases when the composite electrodes are prepared via a solution process. The lithium silicate coating and the use of a high-Li-ion additive conductor are also important to reduce the interfacial resistance and achieve high initial capacities (140 mAh g−1).
• Cd additive effect on self-flux growth of Cs-intercalated NbS2superconducting single crystals

  Masanori Nagao, Akira Miura, Yuki Maruyama, Satoshi Watauchi, Yoshihiko Takano, Isao Tanaka

  Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences 76 (10-12) 739 - 743 1865-7117 2021/11/01 

  Single crystals of Cs-intercalated NbS2 (Cs x NbS2) were synthesized using a CsCl/KCl self-flux. The size and Cs content of Cs x NbS2 single crystals increased upon adding Cd metal into the starting materials. When 10-30 at% of Cd per Nb was provided in the starting materials, plate-like Cs x NbS2 (x ∼0.3) single crystals with 1-2 mm in size and 10-100 μm in thickness were obtained. The superconducting transition temperature of these Cs x NbS2 single crystals was 1.65 K.
• Bipolar doping and thermoelectric properties of Zintl arsenide Eu5In2As6

  Naoki Tomitaka, Yosuke Goto, Kota Morino, Kazuhisa Hoshi, Yuki Nakahira, Hiroaki Ito, Akira Miura, Hidetomo Usui, Yoshikazu Mizuguchi

  JOURNAL OF MATERIALS CHEMISTRY A 9 (46) 26362 - 26370 2050-7488 2021/11 

  Zintl compounds exhibit promising thermoelectric properties because of the feasibility of the chemical tuning of their electrical and thermal transport. While most Zintl pnictides are known to show p-type polarity, recent developments in high-performance n-type Mg3Sb2-based thermoelectric materials have encouraged further identification of n-type Zintl pnictides. In this study, we demonstrate the bipolar dopability of Zintl arsenide Eu5In2As6. The electrical resistivity at 300 K with n-type polarity was decreased to 7.6 x 10(-1) omega cm using La as an electron dopant. In contrast to the relatively high resistivity of n-type Eu5In2As6, the p-type resistivity at 300 K was decreased to 5.9 x 10(-3) omega cm with a carrier concentration of 2.8 x 10(20) cm(-3) using Zn as a hole dopant. This doping asymmetry is discussed in terms of the weighted mobility of electrons and holes. Furthermore, a very low lattice thermal conductivity of 0.7 W m(-1) K-1 was observed at 773 K, which is comparable to that of the Sb-containing analogue Eu5In2Sb6. The dimensionless figure of merit ZT = 0.29 at 773 K was obtained for Zn-doped p-type Eu5In2As6. This study shows that bipolar dopable Eu5In2As6 can be a platform to facilitate a better understanding of the doping asymmetry in Zintl pnictides.
• Fluorine solubility and superconducting properties of Sm(O,F)BiS2 single crystals

  Akira Miura

  ArXiv 883 160812 - 160812 0925-8388 2021/11 [Refereed]
  
• Synthesis of highly Li-ion conductive garnet-type solid ceramic electrolytes by solution-process-derived sintering additives

  Nataly Carolina Rosero-Navarro, Haruna Watanabe, Akira Miura, Kiyoharu Tadanaga

  Journal of the European Ceramic Society 41 (13) 6767 - 6771 0955-2219 2021/10 [Refereed]
   

  The sintering and processing of garnet-type solid ceramic electrolytes (e.g., Li7La3Zr2O12 (LLZ)) are challenging because the material composition and microstructure at high temperatures must be carefully controlled to obtain the stabilization of highly conductive cubic phase and dense ceramic. Liquid-phase sintering using sintering aids is typically used for densifying ceramic materials, as it is a faster and/or lower-temperature process. In this study, we used solution-process-derived sintering additives to sinter garnet-type solid electrolytes highly effective in terms of relative density and properties at 1000 degrees C (10 h). The liquid phase formation during the sintering was rationalized to establish the optimal sintering conditions. The use of 1.2-vol% 75Li(2)O center dot 25B(2)O(3) and 1.5-vol% Al2O3 as sintering additives was highly effective in densifying a Ta-doped LLZ, achieving a high ionic conductivity of 0.8 mS cm(-1) (25 degrees C) with low activation energy (9 kJ mol(-1)) and almost negligible contribution of the grain boundary resistance (10 %).
• Argyrodite solid electrolyte-coated graphite as anode material for all-solid-state batteries

  Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  Journal of Sol-Gel Science and Technology 0928-0707 2021/09/16 [Refereed]
  
• Combustion Reactions between Transition-Metal Chlorides and Sodium Amide and Their Ignition Temperature

  Shinji Noguchi, Jin Odahara, Hayato Sakai, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  Inorganic Chemistry 60 (17) 12753 - 12758 0020-1669 2021/09/06 [Refereed]
  
• n-Type thermoelectric metal chalcogenide (Ag,Pb,Bi)(S,Se,Te) designed by multi-site-type high-entropy alloying

  Aichi Yamashita, Yosuke Goto, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshikazu Mizuguchi

  Materials Research Letters 9 (9) 366 - 372 2166-3831 2021/09/02 [Refereed]
   

  A metal chalcogenide (Ag,Pb,Bi)(S,Se,Te) with an NaCl-type structure was designed by multi-site-type high-entropy alloying (MST-HEA), and the thermoelectric properties were investigated. In this material, both cation and anion sites were alloyed and thus its total entropy of mixing Delta S (mix) (total) achieved 2.00R (R: gas constant). It was found that present sample is an n-type semiconductor with ultra-low lattice thermal conductivity (kappa (L)) of 0.62 Wm(-1)K(-1) at room temperature and 0.46 Wm(-1)K(-1) at T = 723 K. Very low kappa (L) and good power factor resulted in figure of merit of 0.54 at T = 723 K.IMPACT STATEMENTWe report on the material design synthesis and thermoelectric properties on new high-entropy alloy-type compound with an NaCl-type structure (Ag,Pb,Bi)(S,Se,Te)
• Toward the Development of a High-Voltage Mg Cathode Using a Chromium Sulfide Host

  Akira Miura

  ACS Materials Letters 3 (8) 1213 - 1220 2639-4979 2021/08/02 [Refereed]
  
• Kinetically Stabilized Cation Arrangement in Li3YCl6 Superionic Conductor during Solid‐State Reaction

  Hiroaki Ito, Kazuki Shitara, Yongming Wang, Kotaro Fujii, Masatomo Yashima, Yosuke Goto, Chikako Moriyoshi, Nataly Carolina Rosero‐Navarro, Akira Miura, Kiyoharu Tadanaga

  Advanced Science 8 (15) 2101413 - 2101413 2198-3844 2021/08 [Refereed]
  
• Thermoelectric Properties of the As/P-Based Zintl Compounds EuIn2As2–xPx (x = 0–2) and SrSn2As2

  Keisuke Shinozaki, Yosuke Goto, Kazuhisa Hoshi, Ryosuke Kiyama, Naoto Nakamura, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Hidetomo Usui, Yoshikazu Mizuguchi

  ACS Applied Energy Materials 4 (5) 5155 - 5164 2574-0962 2021/05/24 [Refereed]
   

  Zintl compounds containing Sb have been studied extensively because of their promising thermoelectric properties. In this study, we prepared As/P-based Zintl compounds, EuIn2As2-xPx (x = 0-2) and SrSn2As2, and examined their potential for use as thermoelectric materials. These compounds show p-type polarity with Hall carrier concentrations of similar to 10(19) cm(-3) for EuIn2As2-xPx and similar to 10(21) cm(-3) for SrSn2As2 at 300 K. The high carrier concentration of SrSn2As2 is likely due to self-doping by hole-donating Sn vacancies. The electrical power factor reaches similar to 1 mW m(-1) K-2 at similar to 600 K for EuIn2As2-xPx with x = 0.1 and 0.2, which is almost twice that of the end-member compounds (x = 0 and 2). The lattice thermal conductivity kappa(l) is determined to be 1.6-2.0 W m(-)1 K-1 for EuIn2As2 and SrSn2As2 and 2.8 W m(-1) K-1 for EuIn2P2 at 673 K. The dimensionless figure of merit reaches ZT = 0.29 at 773 K for EuIn2As2-xPx with x = 0.2, owing to the optimized carrier concentration and/or electronic structure, as well as reduced lattice thermal conductivity in the solid solution. First-principles calculations show that EuIn2As2 and SrSn2As2 are topologically nontrivial materials with band inversion, while EuIn2P2 is a conventional semiconductor with a band gap. The present study demonstrates that As/P-based Zintl compounds can also show promising thermoelectric properties, thus expanding the frontier for efficient thermoelectric materials.
• Observing and Modeling the Sequential Pairwise Reactions that Drive Solid‐State Ceramic Synthesis

  Akira Miura, Christopher J. Bartel, Yosuke Goto, Yoshikazu Mizuguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yongming Wang, Toshie Yaguchi, Manabu Shirai, Masanori Nagao, Nataly Carolina Rosero‐Navarro, Kiyoharu Tadanaga, Gerbrand Ceder, Wenhao Sun

  Advanced Materials 2100312 - 2100312 0935-9648 2021/05/05 [Refereed]
   

  Solid-state synthesis from powder precursors is the primary processing route to advanced multicomponent ceramic materials. Designing reaction conditions and precursors for ceramic synthesis can be a laborious, trial-and-error process, as heterogeneous mixtures of precursors often evolve through a complicated series of reaction intermediates. Here, ab initio thermodynamics is used to model which pair of precursors has the most reactive interface, enabling the understanding and anticipation of which non-equilibrium intermediates form in the early stages of a solid-state reaction. In situ X-ray diffraction and in situ electron microscopy are then used to observe how these initial intermediates influence phase evolution in the synthesis of the classic high-temperature superconductor YBa Cu O (YBCO). The model developed herein rationalizes how the replacement of the traditional BaCO precursor with BaO redirects phase evolution through a low-temperature eutectic melt, facilitating the formation of YBCO in 30 min instead of 12+ h. Precursor selection plays an important role in tuning the thermodynamics of interfacial reactions and emerges as an important design parameter in planning kinetically favorable synthesis pathways to complex ceramic materials. 2 3 6+ x 3 2
• Phase transition, magnetic, and electronic properties of CeOInS₂

  Hiroki ITO, Akira MIURA, Yosuke GOTO, Yoshikazu MIZUGUCHI, Chikako MORIYOSHI, Yoshihiro KUROIWA, Nataly Carolina ROSERO-NAVARRO, Kiyoharu TADANAGA

  Journal of the Ceramic Society of Japan 129 (5) 249 - 253 1882-0743 2021/05/01 [Refereed]
   

  The magnetic and electronic properties of CeOInS and their influence on phase transition were analyzed in this study. High-temperature XRD measurements of CeOInS revealed that orthorhombic CeOInS transformed into tetragonal CeOInS at a high temperature of 636 K. The transport properties of CeOInS showed semiconducting behavior, with a larger temperature dependence of electronic resistivity in the tetragonal phase compared to that in the orthorhombic phase. Unlike structurally similar Ce(O,F)BiS superconductors that show long-range magnetic ordering, CeOInS neither exhibited superconductive transition nor long-range magnetic ordering at temperatures between 2 and 300 K. 2 2 2 2 2 2 2
• Formation Mechanism of β-Li3PS4 through Decomposition of Complexes

  Marcela Calpa, Hiroshi Nakajima, Shigeo Mori, Yosuke Goto, Yoshikazu Mizuguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  Inorganic Chemistry 60 (10) 6964 - 6970 0020-1669 2021/04/29 [Refereed]
  
• Ultrahigh-Pressure Preparation and Catalytic Activity of MOF-Derived Cu Nanoparticles

  Ichiro Yamane, Kota Sato, Ryoichi Otomo, Takashi Yanase, Akira Miura, Taro Nagahama, Yuichi Kamiya, Toshihiro Shimada

  Nanomaterials 11 (4) 1040 - 1040 2021/04/19 [Refereed]
   

  A metal–organic framework (MOF) consisting of Cu-benzenetricarboxylic acid was processed under ultrahigh pressure (5 GPa) and at temperature of up to 500 °C. The products were characterized with TEM, FTIR, and XAFS. The decomposition of the MOF started at 200 °C at 5 GPa. This temperature was much lower than that in the vacuum. Single-nanometer Cu nanoparticles were obtained in carbon matrix, which was significantly smaller than the Cu particles prepared at ambient pressure. The catalytic activity for Huisgen cycloaddition was examined, and the sample processed at 5 GPa showed a much improved performance compared with that of the MOF-derived Cu nanoparticles prepared without high pressure.
• Fast discharge-charge properties of FePS3 electrode for all-solid-state batteries using sulfide electrolytes and its stable diffusion path

  Akira Miura

  Functional Materials Letters 14 (03) 2141005 - 2141005 1793-6047 2021/04 [Refereed]
   

  We report the fast discharge–charge cycle of micro-sized FePS₃ electrode particles in all-solid-state batteries (ASSBs) using sulfide electrolytes at 80^∘C. At a current density of 2.04 mA cm[Formula: see text], corresponding to approximately 1 C, the capacity of the FePS₃ electrodes reached [Formula: see text]180 mAh g[Formula: see text] without any electron or lithium-ion conductive additives. Galvanostatic intermittent titration technique (GITT) measurements showed a stable diffusion path of FePS₃ represented by the product of the diffusion coefficient and square of the surface area. These electrochemical properties were compared with those of FeS, whose capacity was lower because of its unstable diffusion path.
• Ternary carbodiimide compound, Ba0.9Sr0.1NCN with distorted rutile-type structure

  Yuji Masubuchi, Suzuka Miyazaki, Kotaro Fujii, Masatomo Yashima, Akira Miura, Mikio Higuchi

  Journal of Solid State Chemistry 296 122000 - 122000 0022-4596 2021/04 [Refereed]
   

  Ternary carbodiimides, Ba1-xSrxNCN (x ​= ​0, 0.1, 0.2, 0.5, 0.8, and 1.0) were prepared by an ammonolysis reaction with a (Ba,Sr)CO3 precursor obtained by a polymerized complex method. A new orthorhombic carbodiimide was obtained at x ​= ​0.1. It coexists with SrNCN-type solid solutions between x ​= ​0.2 and 0.5. The crystal structure of Ba0.9Sr0.1NCN was determined using single-crystal X-ray and powder neutron diffraction data, and was found to adopt an orthorhombic Pnnm crystal structure. In this structure, both Ba2+ and Sr2+ cations are situated in an octahedron of N atoms of NCN2− anionic groups, and the (Ba/Sr)N6 octahedra form a distorted rutile-type structure with C atoms bridging the N atoms.
• Kinetic Control of the Li0.9Mn1.6Ni0.4O4 Spinel Structure with Enhanced Electrochemical Performance

  F. A. Vásquez, N. C. Rosero-Navarro, A. Miura, R. Jalem, Y. Goto, M. Nagao, Y. Tateyama, K. Tadanaga, J. A. Calderón

  ACS Applied Materials & Interfaces Accepted (12) 14056 - 14067 1944-8244 2021/03/16 [Refereed]
  
• Chemical stability of Li4PS4I solid electrolyte against hydrolysis

  Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Randy Jalem, Yoshitaka Tateyama, Kiyoharu Tadanaga

  Applied Materials Today 22 100918 - 100918 2352-9407 2021/03 [Refereed]
  
• The crystal structure and electrical/thermal transport properties of Li1−xSn2+xP2 and its performance as a Li-ion battery anode material

  Yosuke Goto, Shota Nakanishi, Yusuke Nakai, Takeshi Mito, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Hidetomo Usui, Tatsuma D. Matsuda, Yuji Aoki, Yoshifumi Nakacho, Yuto Yamada, Kiyoshi Kanamura, Yoshikazu Mizuguchi

  Journal of Materials Chemistry A 9 (11) 7034 - 7041 2050-7488 2021/02 [Refereed]
   

  The physical and chemical properties of Li_1−xSn_2+xP₂ are affected by Li/Sn mixed occupation with local ordering.

• Wet Chemical Processes for the Preparation of Composite Electrodes in All-Solid-State Lithium Battery

  Kiyoharu Tadanaga, Nataly Carolina Rosero-Navarro, Akira Miura

  Next Generation Batteries 85 - 92 2021
• Synthesis of sulfide solid electrolytes from Li2S and P2S5 in anisole

  Akira Miura

  Journal of Materials Chemistry A 9 (1) 400 - 405 2050-7488 2021 [Refereed]
   

  We report the liquid-phase synthesis of sulfide solid electrolytes from Li₂S and P₂S₅ using anisole at 200–300 °C under microwave irradiation, in which β-Li₃PS₄ and Li₇P₃S₁₁ were directly precipitated in anisole in 30 min.

• Structural Phase Diagram of LaO1−xFxBiSSe: Suppression of the Structural Phase Transition by Partial F Substitutions

  Kazuhisa Hoshi, Shunsuke Sakuragi, Takeshi Yajima, Yosuke Goto, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshikazu Mizuguchi

  Condensed Matter 5 (4) 81 - 81 2020/12/11 [Refereed]
   

  Recently, the anomalous two-fold-symmetric in-plane anisotropy of superconducting states has been observed in a layered superconductor system, LaO1−xFxBiSSe (x = 0.1 and 0.5), with a tetragonal (four-fold symmetric) in-plane structure. To understand the origin of the phenomena observed in LaO1−xFxBiSSe, clarification of the low-temperature structural phase diagram is needed. In this study, we have investigated the low-temperature crystal structure of LaO1−xFxBiSSe (x = 0, 0.01, 0.02, 0.03, and 0.5). From synchrotron X-ray diffraction experiments, a structural transition from tetragonal to monoclinic was observed for x = 0 and 0.01 at 340 and 240 K, respectively. For x = 0.03, a structural transition and broadening of the diffraction peak were not observed down to 100 K. These facts suggest that the structural transition could be suppressed by 3% F substitution in LaO1−xFxBiSSe. Furthermore, the crystal structure for x = 0.5 at 4 K was examined by low-temperature laboratory X-ray diffraction, which confirmed that the tetragonal structure is maintained at 4 K for x = 0.5. Our structural investigation suggests that the two-fold-symmetric in-plane anisotropy of superconducting states observed in LaO1−xFxBiSSe was not originated from structural symmetry lowering in its average structure. To evaluate the possibility of the local structural modification like nanoscale puddles in the average tetragonal structure, further experiments are desired.
• Evolution of two bulk-superconducting phases in Sr0.5RE0.5FBiS2 (RE: La, Ce, Pr, Nd, Sm) by external hydrostatic pressure effect

  Aichi Yamashita, Rajveer Jha, Yosuke Goto, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Chizuru Kawashima, Kouhei Ishida, Hiroki Takahashi, Yoshikazu Mizuguchi

  Scientific Reports 10 (1) 2020/12/01 [Refereed][Not invited]
   

  © 2020, The Author(s). Polycrystalline samples of Sr0.5RE0.5FBiS2 (RE: La, Ce, Pr, Nd, and Sm) were synthesized via the solid-state reaction and characterized using synchrotron X-ray diffraction. Although all the Sr0.5RE0.5FBiS2 samples exhibited superconductivity at transition temperatures (Tc) within the range of 2.1–2.7 K under ambient pressure, the estimated superconducting volume fraction was small, which indicates non-bulk nature of superconductivity in those samples under ambient pressure. A dramatic increase in shielding fraction, which indicates the emergence of the bulk superconductivity was achieved by applying external hydrostatic pressures. We found that two phases, low-P phases with Tc = 2.5–2.8 K and high-P phases with Tc = 10.0–10.8 K, were induced by the pressure effect for samples with RE = La, Ce, Pr, and Nd. Pressure-Tc phase diagrams indicated that the critical pressure for the emergence of the high-P phase tends to increase with decreasing ionic radius of the doped RE ions, which was explained by the correlation between external and chemical pressure effects. According to the high-pressure X-ray diffraction measurements of Sr0.5La0.5FBiS2, a structural phase transition from tetragonal to monoclinic also occurred at approximately 1.1 GPa. Bulk superconducting phases in Sr0.5RE0.5FBiS2 induced by the external hydrostatic pressure effect are expected to be useful for understanding the effects of both external and chemical pressures to the emergence of bulk superconductivity and pairing mechanisms in BiCh2-based superconductors.
• Formation Mechanism of Thiophosphate Anions in the Liquid-Phase Synthesis of Sulfide Solid Electrolytes Using Polar Aprotic Solvents

  Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kota Terai, Futoshi Utsuno, Kiyoharu Tadanaga

  Chemistry of Materials 32 (22) 9627 - 9632 0897-4756 2020/11/24 [Refereed]
  
• Organic–Inorganic Hybrid Materials for Interface Design in All-Solid-State Batteries with a Garnet-Type Solid Electrolyte

  Nataly Carolina Rosero-Navarro, Ryunosuke Kajiura, Akira Miura, Kiyoharu Tadanaga

  ACS Applied Energy Materials 3 (11) 11260 - 11268 2574-0962 2020/11/23 [Refereed]
  
• Growth and anisotropy evaluation of NbBiCh(3) (Ch = S, Se) misfit-layered superconducting single crystals

  Akira Miura

  Solid State Communications 321 114051 - 114051 0038-1098 2020/11 [Refereed]
  
• Two-fold symmetry of in-plane magnetoresistance anisotropy in the superconducting states of BiCh₂-based LaO_0.9F_0.1BiSSe single crystal

  Akira Miura

  Journal of Physics Communications 4 (9) 095028 - 095028 2020/10/06 [Refereed]
  
• Improvement of superconducting properties by chemical pressure effect in Eu-doped La2-xEuxO2Bi3Ag0.6Sn0.4S6

  Akira Miura

  Physica C: Superconductivity and its Applications 576 1353731 - 1353731 0921-4534 2020/09 [Refereed][Not invited]
  
• Growth and Characterization of ROBiS2 High-Entropy Superconducting Single Crystals

  Yuma Fujita, Koki Kinami, Yuji Hanada, Masanori Nagao, Akira Miura, Shigeto Hirai, Yuki Maruyama, Satoshi Watauchi, Yoshihiko Takano, Isao Tanaka

  ACS Omega 5 (27) 16819 - 16825 2470-1343 2020/07/14 [Refereed][Not invited]
   

  A series of high-entropy superconductors, ROBiS2 (R = La + Ce + Pr + Nd + Sm), have been successfully grown in the form of single crystals using CsCl flux. The obtained single crystals have a platelike shape with a size of 0.5-2.0 mm and a thickness of 70-450 mu M, and they are cleavable along the c-plane. The c-axis lattice constants of the obtained ROBiS2 single crystals have similar values of 13.47-13.57 angstrom. The Ce in the obtained ROBiS2 single crystals was in a mixed-valence state, comprising both Ce(3+ )and Ce4+. On the other hand, Pr and Sm showed only the trivalent state. The superconducting transition temperatures of ROBiS2 single crystals were approximately 2-4 K. The superconducting transition temperature and superconducting anisotropies of R-site mixed high-entropy samples increased with a decrease in the mean ionic radius of the R-site. Moreover, a deviation in the tendency to exhibit superconducting properties was observed based on the difference in the R-site mixed entropy. R-site mixed entropy in ROBiS2 superconductors may affect their superconducting properties.
• Synthesis and ionic conductivity of a high-entropy layered hydroxide

  Akira Miura

  Journal of the Ceramic Society of Japan 128 (7) 336 - 339 1882-0743 2020/07/01 [Refereed][Not invited]
  
• Bulk Superconductivity Induced by Se Substitution in Self-Doped BiCh(2)-Based Compound CeOBiS2-xSex

  Akira Miura

  Journal of the Physical Society of Japan 89 (6) 064702 - 064702 0031-9015 2020/06/15 [Refereed][Not invited]
  
• Significant Reduction in the Interfacial Resistance of Garnet-Type Solid Electrolyte and Lithium Metal by a Thick Amorphous Lithium Silicate Layer

  Nataly Carolina Rosero-Navarro, Ryunosuke Kajiura, Randy Jalem, Yoshitaka Tateyama, Akira Miura, Kiyoharu Tadanaga

  ACS Applied Energy Materials 3 (6) 5533 - 5541 2574-0962 2020/05/27 [Refereed][Not invited]
  
• Crystal Structure and Thermoelectric Transport Properties of As-Doped Layered Pnictogen Oxyselenides NdO0.8F0.2Sb1-xAsxSe2

  Akira Miura

  Materials 13 (9) 2164 - 2164 2020/05/07 [Refereed]
   

  We report the synthesis and thermoelectric transport properties of As-doped layered pnictogen oxyselenides NdO0.8F0.2Sb1−xAsxSe2 (x ≤ 0.6), which are predicted to show high-performance thermoelectric properties based on first-principles calculation. The crystal structure of these compounds belongs to the tetragonal P4/nmm space group (No. 129) at room temperature. The lattice parameter c decreases with increasing x, while a remains almost unchanged among the samples. Despite isovalent substitution of As for Sb, electrical resistivity significantly rises with increasing x. Very low thermal conductivity of less than 0.8 Wm−1K−1 is observed at temperatures between 300 and 673 K for all the examined samples. For As-doped samples, the thermal conductivity further decreases above 600 K. Temperature-dependent synchrotron X-ray diffraction indicates that an anomaly also occurs in the c-axis length at around 600 K, which may relate to the thermal transport properties.
• Selective metathesis synthesis of MgCr2S4 by control of thermodynamic driving forces

  Akira Miura

  Materials Horizons 7 (5) 1310 - 1316 2051-6347 2020/05/01 [Refereed][Not invited]
   

  By altering the thermodynamic landscape, metathesis enables the rapid and selective synthesis of MgCr₂S₄ thiospinel, a compelling Mg-cathode material that is laborious to make via traditional ceramic synthesis routes.

• Fe-P-S electrodes for all-solid-state lithium secondary batteries using sulfide-based solid electrolytes

  Akira Miura

  Journal of Power Sources 449 (15) 227576 - 227576 2020/02 [Refereed][Not invited]
  
• Electrical properties of pyrochlore-type silver tantalate and fluorite-type silver niobate

  Akira Miura

  Journal of the Ceramic Society of Japan 128 (1) 46 - 50 1882-0743 2020/01/01 [Refereed][Not invited]
  
• Flux Growth and Superconducting Properties of (Ce,Pr)OBiS2 Single Crystals

  Akira Miura

  Frontiers in Chemistry 8 00044  2020 [Refereed][Not invited]
  
• Redox reactions of small organic molecules using ball milling and piezoelectric materials

  Hajime Ito, Koji Kubota, Yadong Pang, Akira Miura, Hajime Ito

  Science 366 (6472) 1500 - 1504 2019/12/20 [Refereed][Not invited]
  
• Growth of Superconducting Sm(O,F)BiS2 Single Crystals

  Akira Miura

  Crystal Growth & Design 19 (11) 6136 - 6140 1528-7483 2019/11/06 [Refereed][Not invited]
  
• Enhanced hydroxide ion conductivity of Mg-Al layered double hydroxide at low humidity by intercalating dodecyl sulfate anion

  Akira Miura

  Journal of the Ceramic Society of Japan 127 (11) 788 - 792 1882-0743 2019/11 [Refereed][Not invited]
  
• Mg-Al layered double hydroxide as an electrolyte membrane for aqueous ammonia fuel cell

  Akira Miura

  Materials Research Bulletin 119 110561  2019/11 [Refereed][Not invited]
  
• Pressure-induced superconductivity in the layered pnictogen diselenide NdO0.8F0.2Sb1-xBixSe2 (x=0.3 and 0.7)

  Matsumoto Ryo, Goto Yosuke, Yamamoto Sayaka, Sudo Kenta, Usui Hidetomo, Miura Akira, Moriyoshi Chikako, Kuroiwa Yoshihiro, Adachi Shintaro, Irifune Tetsuo, Takeya Hiroyuki, Tanaka Hiromi, Kuroki Kazuhiko, Mizuguchi Yoshikazu, Takano Yoshihiko

  PHYSICAL REVIEW B 100 (9) 094528  2469-9950 2019/09 [Refereed][Not invited]
  
• Two-Dimensional Hybrid Halide Perovskite as Electrode Materials for All-Solid-State Lithium Secondary Batteries Based on Sulfide Solid Electrolytes

  Akira Miura

  ACS Applied Energy Materials 2 (9) 6569 - 6576 2019/08 [Refereed][Not invited]
  
• Hydrothermal synthesis of KTi2(PO4)(3), alpha-Ti(HPO4)(2)center dot H2O and gamma-Ti(PO4)(H2PO4)center dot 2H(2)O from a lepidocrocite-type titanate

  Akira Miura

  Journal Of Asian Ceramic Societies 7 (3) 361 - 367 2019/08 [Refereed][Not invited]
  
• Growth and transport properties under high pressure of PrOBiS2 single crystals

  Akira Miura

  Solid State Communications 296 17 - 20 2019/07 [Refereed][Not invited]
  
• Enhanced superconductivity by Na doping in SnAs-based layered compound Na1+xSn2-xAs2

  Akira Miura

  Japanese Journal of Applied Physics 58 (1) 083001  2019/07 [Refereed][Not invited]
  
• An electronic structure governed by the displacement of the indium site in In–S6 octahedra: LnOInS2 (Ln = La, Ce, and Pr)

  Ito, Hiroaki, Miura, Akira, Goto, Yosuke, Mizuguchi, Yoshikazu, Moriyoshi,Chikako, Kuroiwa, Yoshihiro, Azuma, Masaki, Liu, Jinjia, Wen, Xiao-Dong, Nishioka,Shunta, Maeda, Kazuhiko, Masubuchi, Yuji, Rosero-Navarro, Nataly Carolina, Tadanaga, Kiyoharu

  Dalton Transactions 48 (32) 12272 - 12278 1477-9226 2019/06 [Refereed][Not invited]
   

  An extremely large displacement of the indium site in In-S-6 octahedra in LnOInS(2) (Ln = La, Ce, and Pr) was found in synchrotron X-ray diffraction. LaOInS2 with off-center indium in In-S-6 octahedra exhibited a wider optical band gap than CeOInS2 and PrOInS2 with on-center indium. Therefore, the electronic structure of LnOInS(2) is governed by the indium site with an extremely large displacement. All LnOInS(2) produced H-2 gas under visible light irradiation in the presence of sacrificial electron donors.
• Self-Combustion Synthesis of Novel Metastable Ternary Molybdenum Nitrides

  Akira Miura

  ACS Materials Letters 1 64 - 70 2019/06 [Refereed][Not invited]
  
• Improvement of superconducting properties by high mixing entropy at blocking layers in BiS2-based superconductor REO0.5F0.5BiS2

  Akira Miura

  Solid State Communications 295 43 - 49 2019/06 [Refereed][Not invited]
  
• Growth and characterization of (La,Ce)OBiS2 single crystals

  Akira Miura

  Japanese Journal of Applied Physics 58 (6) 063001  2019/05 [Refereed][Not invited]
  
• Composition, valence and oxygen reduction reaction activity of Mn-based layered double hydroxides

  Akira Miura

  Journal Of Asian Ceramic Societies 7 (2) 147 - 153 2019/05 [Refereed][Not invited]
  
• Catalytic Activity for Oxygen Reduction Reaction of Ni-Mn-Fe Layered Double Hydroxide-Carbon Gel Composite

  Iwai, Yu, Ikka, Takuya, Miura, Akira, Rosero-Navarro, Nataly Carolina, Iwamura, Shinichiroh, Ogino, Isao, Mukai, R. Mukai, Tadanaga, Kiyoharu

  Chemistry Letters 48 (7) 696 - 699 0366-7022 2019/04 [Refereed][Not invited]
  
• Doping-Induced Polymorph and Carrier Polarity Changes in Thermoelectric Ag(Bi,Sb)Se-2 Solid Solution

  Akira Miura

  Inorganic Chemistry 58 (11) 7628 - 7633 2019/04 [Refereed][Not invited]
  
• Liquid-phase syntheses of sulfide electrolytes for all-solid-state lithium battery

  Miura, Akira, Rosero-Navarro, Nataly Carolina, Sakuda, Atsushi, Tadanaga, Kiyoharu, Phuc, Nguyen H. H, Matsuda, Atsunori, Machida, Nobuya, Hayashi, Akitoshi, Tatsumisago, Masahiro

  Nature Reviews Chemistry 3 (3) 189 - 198 2019/03 [Refereed][Not invited]
   

  Solid sulfide electrolytes are key materials in all-solid-state lithium batteries because of their high lithium-ion conductivity and deformability, which enable the lithium-ion path to be connected between the material’s grain boundaries under pressure near room temperature. However, sulfur species are moisture-sensitive and exhibit high vapour pressures; therefore, syntheses of sulfide electrolytes need to be carefully designed. Liquid-phase reactions can be performed at low temperatures in controlled atmospheres, opening up the prospect of scalable processes for the preparation of sulfide electrolytes. Here, we review liquid-phase syntheses for the preparation of sulfide-based solid electrolytes and composites of electrolytes and electrodes, and we compare the charge–discharge performances of the all-solid-state lithium batteries using these components.
• Effect of Bi Substitution on Thermoelectric Properties of SbSe2-based Layered Compounds NdO0.8F0.2Sb1-xBixSe2

  Akira Miura

  Journal of the Physical Society of Japan 88 (2) 0031-9015 2019/02/15 [Refereed][Not invited]
   

  Although SbSe2-based layered compounds have been predicted to be high-performance thermoelectric materials and topological materials, most of these compounds obtained experimentally have been insulators so far. Here, we present the effect of Bi substitution on the thermoelectric properties of SbSe2-based layered compounds NdO0.8F0.2Sb1-xBixSe2 (x <= 0.4). The room temperature electrical resistivity is decreased to 8.0 x 10(-5) Omega m for x = 0.4. The electrical power factor is calculated to be 1.4 x 10(-1) W m(-1) K-2 at 660 K, which is in reasonable agreement with combined Jonker and Ioffe analysis. The room-temperature lattice thermal conductivity of less than 1 W in(-1) K-1 is almost independent of x, in contrast to the point-defect scattering model for conventional alloys. The present work provides an avenue for exploring SbSe2-based insulating and BiSe2-based conducting systems.
• Growth and physical properties of Ce(O,F)Sb(S,Se)2 single crystals with site-selected chalcogen atoms

  Masanori Nagao, Masashi Tanaka, Akira Miura, Miho Kitamura, Koji Horiba, Satoshi Watauchi, Yoshihiko Takano, Hiroshi Kumigashira, Isao Tanaka

  Solid State Communications 289 38 - 42 0038-1098 2019/02 [Refereed][Not invited]
   

  © 2018 Elsevier Ltd Ce(O,F)Sb(S,Se)2 single crystals were successfully grown using a CsCl/KCl flux method. The obtained crystals have a plate-like shape with the typical size of 1–2 mm and well-developed ab-plane, which enables X-ray single crystal structural analysis. The Ce(O,F)Sb(S,Se)2 crystallizes in a monoclinic space group, P21/m, with lattice parameters of a = 4.121(7) Å, b = 4.109(7) Å, c = 13.233(15) Å, β = 97.94(7) °. It is composed of alternate stacking of Ce-(O,F) and Sb-SSe layers, and the Sb-SSe layer includes selective occupation of Se atoms in its in-plane site. The valence state of Ce is estimated to be Ce3+ by X-ray absorption fine spectroscopy analysis. The single crystals show an insulating behavior, and a magnetic ordering around 6 K.
• Electrochemical performance of bulk-type all-solid-state batteries using small-sized Li7P3S11 solid electrolyte prepared by liquid phase as the ionic conductor in the composite cathode

  Akira Miura

  Electrochimica Acta 296 473  2019/02 [Refereed][Not invited]
  
• Effect of Bi Substitution on Thermoelectric Properties of SbSe2-based Layered Compounds NdO$_{0.8}$F$_{0.2}$Sb$_{1-x}$Bi$_x$Se$_2$

  Akira Miura

  ArXiv 2019
• Ionic conductivity of Pyrochlore-type Silver Tantalate and Fluorite-type Silver Niobate

  W. I, U. WITHANAGE, Nobuhiro Kumada, Takahiro Takei, Sayaka YANAGIDA, Kiyoharu Tadanaga, Akira Miura, Nataly Carolina, Rosero-Navarro, Masaki Azuma

  J. Ceram. Soc. Jpn. in press 2019 [Refereed][Not invited]
  
• Preparation of lithium ion conductive Li6PS5Cl solid electrolyte from solution for the fabrication of composite cathode of all-solid-state lithium battery

  Akira Miura

  Journal of Sol-Gel Science and Technology 89 (1) 303 - 309 2019 [Refereed][Not invited]
  
• Reaction Mechanism of FePS3 Electrodes in All-Solid-State Lithium Secondary Batteries Using Sulfide-Based Solid Electrolytes

  Akira Miura

  Journal of the Electrochemical Society 165 (13) A2948 - A2954 2018/11 [Refereed][Not invited]
  
• Electrochemical performance of a garnet solid electrolyte based lithium metal battery with interface modification

  Akira Miura

  Journal of Materials Chemistry A 6 21018 - 21028 2018/10 [Refereed][Not invited]
   

  国際共同研究
• Composite cathode prepared by argyrodite precursor solution assisted by dispersant agents for bulk-type all-solid-state batteries

  Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  Journal of Power Sources 396 (31) 33 - 40 0378-7753 2018/08/31 [Refereed][Not invited]
   

  All-solid-state lithium batteries based on sulfide solid electrolytes are potential candidates for large-scale energy storage applications. Here, composite cathode with high content of an active material was prepared by a liquid phase process assisted by a dispersant agent to produce a better electrode and electrolyte interface. Li6PS5Cl sulfide electrolyte derived from a solution containing dispersant showed an argyrodite crystal phase with a better distribution of particle size and higher conductivity compared with those without dispersant. Regular distribution of Li6PS5Cl particles in nanometric scale with a spherical shape below 500 nm and conductivity of 0.6 × 10−3 S cm−1 (ρ = 1.40 g cm−3) at room temperature were obtained. Composite cathode was prepared by the dispersion of LiNi1/3Mn1/3Co1/3O2 particles and carbon additive in the Li6PS5Cl-solution containing dispersant agent and subsequent drying at 180 °C. Bulk-type all-solid-state battery fabricated with the composite cathode containing 89 wt% of the active material showed an initial discharge capacity of 110 mA h g−1 at 25 °C and maintained 95% discharge capacity after 15 cycles.
• Na1-xSn2P2 as a new member of van der Waals-type layered tin pnictide superconductors

  Goto, Yosuke, Miura, Akira, Moriyoshi, Chikako, Kuroiwa, Yoshihiro, Matsuda, Tatsuma D, Aoki, Yuji, Mizuguchi, Yoshikazu

  SCIENTIFIC REPORTS NATURE PUBLISHING GROUP 8 (1) 12852 - 12852 2045-2322 2018/08/27 [Refereed][Not invited]
   

  Superconductors with a van der Waals (vdW) structure have attracted a considerable interest because of the possibility for truly two-dimensional (2D) superconducting systems. We recently reported NaSn2As2 as a novel vdW-type superconductor with transition temperature (T-c) of 1.3 K. Herein, we present the crystal structure and superconductivity of new material Na1-xSn2P2 with T-c = 2.0 K. Its crystal structure consists of two layers of a buckled honeycomb network of SnP, bound by the vdW forces and separated by Na ions, as similar to that of NaSn2As2. Amount of Na deficiency (x) was estimated to be 0.074(18) using synchrotron X-ray diffraction. Bulk nature of superconductivity was confirmed by the measurements of electrical resistivity, magnetic susceptibility, and specific heat. First-principles calculation using density functional theory shows that Na1-xSn2P2 and NaSn2As2 have comparable electronic structure, suggesting higher Tc of Na1-xSn2P2 resulted from increased density of states at the Fermi level due to Na deficiency. Because there are various structural analogues with tin-pnictide (SnPn) conducting layers, our results indicate that SnPn-based layered compounds can be cate
• Synthesis of submicron-sized NiPS3 particles and electrochemical properties as active materials in all-solid-state lithium batteries

  Akira Miura

  Journal of the Ceramic Society of Japan 126 (7) 568 - 572 1348-6535 2018/07/01
• Synthesis of Bi-2(O,F)S-2 superconductors by NaF treatment

  Akira Miura

  Journal of the Ceramic Society of Japan 126 (7) 591 - 593 2018/07 [Refereed][Not invited]
  
• Oxygen vacancy-originated highly active electrocatalysts for the oxygen evolution reaction

  Hirai, Shigeto, Morita, Kazuki, Yasuoka, Kenji, Shibuya, Taizo, Tojo, Yujiro, Kamihara, Yoichi, Miura, Akira, Suzuki, Hisao, Ohno, Tomoya, Matsuda, Takeshi, Yagi, Shunsuke

  Journal of Materials Chemistry A 6 (31) 15102 - 15109 2050-7488 2018/07 [Refereed][Not invited]
   

  The oxygen evolution reaction (OER) is an important reaction in the field of renewable energy and is utilized in electrochemical water splitting for hydrogen fuel production and rechargeable metal-air batteries. Herein, we report a new oxygen evolution reaction mechanism originating from oxygen vacancies, which remarkably enhances the OER activity of oxygen deficient electrocatalysts. The OER activity of Sr2VFeAsO3- is drastically enhanced above the lattice oxygen vacancy of = 0.5, exhibiting approximate to 300 mV lower overpotential and 80 times higher specific activity at 1.7 V vs. RHE. Surprisingly, the initially low OER activity of Sr2VFeAsO3- ( < 0.5) is enhanced to the level of state-of-the-art OER catalysts simply by introducing higher concentrations of oxygen vacancies. Density functional theory (DFT) calculations clarify that the oxygen vacancies are initially dominated by one of the crystallographic sites, while two types of crystallographic sites become fully accessible for > 0.5. As a result, the distance between OH- coupled oxygen-vacant sites becomes sufficiently short to enable direct O-O bond formation as in photosystem II. Thus, we found that the OER activity of oxygen deficient electrocatalysts is controllable by the variety of lattice oxygen vacancies, which suggests that oxygen deficient layered superconductors are promising OER catalysts for energy conversion technologies.
• Float zone growth and spectroscopic properties of Yb:CaYAlO4 single crystal for ultra-short pulse lasers

  Moe Narita, Mikio Higuchi, Takayo Ogawa, Satoshi Wada, Akira Miura, Kiyoharu Tadanaga

  Optical Materials 80 57 - 61 0925-3467 2018/06/01 [Refereed][Not invited]
   

  Yb:CaYAlO4 single crystals were grown by the floating zone method and their spectral properties were investigated. Void formation was effectively suppressed by using a feed rod of Y-rich composition with the aid of a double zone-pass technique. For the oxygen excess composition of Yb:Ca0.9925Y1.0075AlO4.00375, a void-free crystal was obtained by performing only the double zone-pass. On the other hand, for cation-deficient type of Yb:Ca0.9925Y1.005AlO4, void-free crystal could not be obtained by performing the double zone-pass. The void formation is attributable to the constitutional supercooling caused by segregation of main constituents of Y and Ca, and the congruent composition may exist in the Y-rich region with existence of interstitial excess oxide ions. The absorption cross section for σ-polarization was slightly larger than that for π-polarization, which is reasonable on the basis of the crystal structure of CaYAlO4.
• Synthesis, crystal structure and optical absorption of NaInS2-xSex

  Akira Miura

  Journal of Alloys and Compounds 750 (25) 409 - 413 2018/06 [Refereed][Not invited]
  
• Crystal Structure and Superconductivity of Tetragonal and Monoclinic Ce1- xPrxOBiS2

  Akira Miura, Masanori Nagao, Yosuke Goto, Yoshikazu Mizuguchi, Tatsuma D. Matsuda, Yuji Aoki, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshihiko Takano, Satoshi Watauchi, Isao Tanaka, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  Inorganic Chemistry 57 (9) 5364 - 5370 1520-510X 2018/05/07 [Refereed][Not invited]
   

  Ce1-xPrxOBiS2 powders and Ce0.5Pr0.5OBiS2 single crystals were synthesized and their structure and superconductive properties were examined by X-ray diffraction, X-ray absorption, electronic resistivity, and magnetization. While PrOBiS2 was found to be in a monoclinic phase with one-dimensional Bi-S zigzag chains showing no superconductive transition above 0.1 K, CeOBiS2 was in a tetragonal phase with two-dimensional Bi-S planes showing zero resistivity below 1.3 K. In the range x = 0.3-0.9 in Ce1-xPrxOBiS2, both monoclinic and tetragonal phases were formed together with zero resistivity up to a maximum temperature of 2.2 K. A Ce0.5Pr0.5OBiS2 single crystal, which showed both zero resistivity and a decrease in magnetization at ∼2.4 K, presented a tetragonal structure. Short Bi-S bonding in flat two-dimensional Bi-S planes and mixed Ce3+/Ce4+ were characteristic features of the Ce0.5Pr0.5OBiS2 single crystal, which presumably triggered its superconductivity.
• Structural and Electrochemical Evaluation of Three- and Two-Dimensional Organohalide Perovskites and Their Influence on the Reversibility of Lithium Intercalation

  Daniel Ramirez, Yusaku Suto, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga, Franklin Jaramillo

  Inorganic Chemistry 57 (7) 4181 - 4188 1520-510X 2018/04/02 [Refereed][Not invited]
   

  Organic-inorganic hybrid perovskite materials have recently been investigated in a variety of applications, including solar cells, light emitting devices (LEDs), and lasers because of their impressive semiconductor properties. Nevertheless, the perovskite structure has the ability to host extrinsic elements, making its application in the battery field possible. During the present study, we fabricated and investigated the electrochemical properties of three-dimensional (3D) methylammonium lead mixed-halide CH3NH3PbI3-xBrx and two-dimensional (2D) propylammonium-methlylammonium lead bromide (CH3NH3)2(CH3(CH2)2NH3)2Pb3Br10 hybrid perovskite thin films as electrode materials for Li-ion batteries. These electrodes were obtained by solution processing at 100 °C. CH3NH3PbBr3 achieved high discharge/charge capacities of ∼500 mA h g-1 /160 mA h g-1 that could account also for other processes taking place during the Li intercalation. It was also found that bromine plays an important role for lithium intercalation, while the new 2D (CH3NH3)2(CH3(CH2)2NH3)2Pb3Br10 with a layered structure allowed reversibility of the lithium insertion-extraction of 100% with capacities of ∼375 mA h g-1 in the form of a thin film. Results suggest that tuning the composition of these materials can be used to improve intercalation capacities, while modification from 3D to 2D layered structures contributes to improving lithium extraction. The mechanism of the lithium insertion-extraction may consist of an intercalation mechanism in the hybrid material accompanying the alloying-dealloying process of the LixPb intermetallic compounds. This work contributes to revealing the relevance of both composition and structure of potential hybrid perovskite materials as future thin film electrode materials with high capacity and compositional versatility.
• Preparation of sulfide solid electrolytes in the Li2S-P2S5 system by a liquid phase process

  Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  Inorganic Chemistry Frontiers 5 (2) 501 - 508 2052-1553 2018/02/01 [Refereed][Not invited]
   

  Sulfide solid electrolytes in the Li2S-P2S5 system were synthesized by a liquid phase process under ultrasonic irradiation, and heat treatments at low temperatures. Crystal phase, structure, morphology and ionic conductivity of the sulfide electrolytes were examined after solvent removal at 180 °C and two different heat treatment temperatures, 220 °C and 250 °C. The study revealed that the ionic conductivities of the xLi2S·(100 - x)P2S5 sulfide electrolytes, in compositions with 70 ≤ x ≤ 75 mol%, are largely influenced by the local structure. The heat treatment at 220 °C was found to be an adequate temperature to promote crystallization of the high ionic conductive Li7P3S11 phase. Higher temperatures for heat treatment such as 250 °C lead to the formation of P2S6 4- (hypo-thiodiphosphate) units in the local structure of the sulfide electrolytes leading to a reduction of ionic conductivity. The formation and distribution of PS4 3- (ortho-thiophosphate), P2S7 4- (pyro-thiophosphate) and P2S6 4- units in the local structure were found to be key factors in achieving higher ionic conductivity (up to 10-3-10-4 S cm-1 at room temperature).
• Explosive Reaction for Barium Niobium Perovskite Oxynitride

  Jin Odahara, Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  Inorganic Chemistry 57 (1) 24 - 27 1520-510X 2018/01/02 [Refereed][Not invited]
   

  An intense exothermic and explosive reaction between Ba(OH)2, NbCl5, and NaNH2 produced barium niobium perovskite oxynitride in seconds. The addition of hexane reduced the risk of explosion during mixing of the starting materials, and subsequent heat treatment at 498 K in hexane allowed control of this exothermic reaction, leading to formation of the perovskite oxynitride with fewer impurities. The synthesis of barium tantalum perovskite oxynitride under similar reaction conditions was successful.
• Synthesis, crystal structure, and thermoelectric properties of layered antimony selenides reosbse2 (RE = La, Ce)

  Yosuke Goto, Akira Miura, Ryosuke Sakagami, Yoichi Kamihara, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshikazu Mizuguchi

  Journal of the Physical Society of Japan 87 (7) 074703  1347-4073 2018 [Refereed][Not invited]
   

  Inspired by the recent first-principles calculations showing the high thermoelectric performance of layered pnictogen chalcogenides, we experimentally characterise the crystal structure and high-temperature transport properties of the layered antimony selenides REOSbSe2 (RE = La, Ce). The crystal structure of REOSbSe2 was the tetragonal P4=nmm space group, consisting of alternate stacks of SbSe2 and REO layers. These two compounds were n-type semiconductors. The optical band gaps of LaOSbSe2 and CeOSbSe2 were evaluated to be 1.0 and 0.6 eV, respectively. The room-temperature thermal conductivity was 1.5 W m−1 K−1 for RE = La and 0.8 W m−1 K−1 for RE = Ce. These relatively low thermal conductivities were comparable to those of isostructural layered bismuth chalcogenides. We substituted O2− with F− ions to introduce electrons as charged carriers to optimize the thermoelectric performance, but increasing the electrical conductivity was still challenging.
• Effect of Te substitution on crystal structure and transport properties of AgBiSe2 thermoelectric material

  Y. Goto, A. Nishida, H. Nishiate, M. Murata, C. H. Lee, A. Miura, C. Moriyoshi, Y. Kuroiwa, Y. Mizuguchi

  Dalton Transactions 47 (8) 2575 - 2580 1477-9234 2018 [Refereed][Not invited]
   

  Silver bismuth diselenide (AgBiSe2) has attracted much attention as an efficient thermoelectric material, owing to its intrinsically low lattice thermal conductivity. While samples synthesized using a solid-state reaction showed n-type conductivity and their dimensionless figure of merit (ZT) reached ∼1 by electron doping, theoretical calculations predicted that a remarkably high thermoelectric performance can be achieved in p-type AgBiSe2. In this paper, we present the effect of Te substitution on the crystal structure and thermoelectric properties of AgBiSe2, expecting p-type conductivity due to the shallowing of the energy potential of the valence band. We found that all AgBiSe2-xTex (x = 0-0.8) prepared using a solid-state reaction exhibits n-type conductivity from 300 to 750 K. The room-temperature lattice thermal conductivity decreased to as low as 0.3 W m-1 K-1 by Te substitution, which was qualitatively described using the point defect scattering model for the solid solution. We show that ZT reaches ∼0.6 for x = 0.8 at a broad range of temperatures, from 550 to 750 K, due to the increased power factor, although the carrier concentration has not been optimized yet.
• Evolution of anisotropic displacement parameters and superconductivity with chemical pressure in BiS2-Based REO0.5F0.5BiS2 (RE = La, Ce, Pr, and Nd)

  Yoshikazu Mizuguchi, Kazuhisa Hoshi, Yosuke Goto, Akira Miura, Kiyoharu Tadanaga, Chikako Moriyoshi, Yoshihiro Kuroiwa

  Journal of the Physical Society of Japan 87 (2) 023704  1347-4073 2018 [Refereed][Not invited]
   

  In order to understand the mechanisms behind the emergence of superconductivity by the chemical pressure effect in REO0.5F0.5BiS2 (RE = La, Ce, Pr, and Nd), where bulk superconductivity is induced by the substitutions with a smaller-radius RE, we performed synchrotron powder X-ray diffraction, and analyzed the crystal structure and anisotropic displacement parameters. With the decrease of the RE3+ ionic radius, the in-plane disorder of the S1 sites significantly decreased, very similar to the trend observed in the Se-substituted systems: LaO0.5F0.5BiS2−xSex and Eu0.5La0.5FBiS2−xSex. Therefore, the emergence of bulk superconductivity upon the suppression of the in-plane disorder at the chalcogen sites is a universal scenario for the BiCh2-based superconductors. In addition, we indicated that the amplitude of vibration along the c-axis of the in-plane chalcogen sites may be related to the Tc in the BiCh2-based superconductors.
• Liquid-phase synthesis of Li6PS5Br using ultrasonication and application to cathode composite electrodes in all-solid-state batteries

  Shunjiro Chida, Akira Miura, Nataly Carolina Rosero-Navarro, Mikio Higuchi, Nguyen H. H. Phuc, Hiroyuki Muto, Atsunori Matsuda, Kiyoharu Tadanaga

  CERAMICS INTERNATIONAL 44 (1) 742 - 746 0272-8842 2018/01 [Refereed][Not invited]
   

  Lithium-ion conductive Li6PS5Br is prepared using ultrasonication of Li2S, P2S5 and LiBr in ethyl propionate-ethanol solution and subsequent heating at 453 K. The main phase of the synthesized product is Li6PS5Br and its lithium ion conductivity is 3.4 x 10(-5) S cm(-1) at room temperature. The cathode composite of LiCo1/3Ni1/3Mn1/3O2, Li6PS5Br and vapor grown carbon fiber (VGCF) is prepared via ultrasonication of the Li6PS5Br precursor solution containing LiCo1/3Ni1/3Mn1/3O2 and VGCF, and the all-solid-state lithium battery using this cathode composite is fabricated. The cell exhibits the discharge capacity of 109 mAh g(-1) for the first cycle and its capacity of 87 mAh g(-1) after 10 cycles.
• Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La2O2Bi3AgS6

  Yudai Hijikata, Tomohiro Abe, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yosuke Goto, Akira Miura, Kiyoharu Tadanaga, Yongming Wang, Osuke Miura, Yoshikazu Mizuguchi

  JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 86 (12) 124802  0031-9015 2017/12 [Refereed][Not invited]
   

  We have synthesized a new layered oxychalcogenide La2O2Bi3AgS6. From synchrotron X-ray diffraction and Rietveld refinement, the crystal structure of La2O2Bi3AgS6 was refined using a model of the P4/nmm space group with a = 4.0644(1) angstrom' and c = 19.412(1) angstrom, which is similar to the related compound LaOBiPbS3, while the interlayer bonds (M2-S1 bonds) are apparently shorter in La2O2Bi3AgS6. The tunneling electron microscopy (TEM) image confirmed the lattice constant derived from Rietveld refinement (c similar to 20 angstrom). The electrical resistivity and Seebeck coefficient suggested that the electronic states of La2O2Bi3AgS6 are more metallic than those of LaOBiS2 and LaOBiPbS3. The insertion of a rock-salt-type chalcogenide into the van der Waals gap of BiS2-based layered compounds, such as LaOBiS2, will be a useful strategy for designing new layered functional materials in the layered chalcogenide family.
• Thermal stability and cutting performance of Al-rich cubic AlxTi1-xN coating prepared by low-pressure chemical vapour deposition

  Anongsack Paseuth, Yasuki Kido, Shinya Imamura, Kazuo Yamagata, Akira Miura, Kiyoharu Tadanaga

  Journal of the Ceramic Society of Japan 125 (12) 913 - 918 1348-6535 2017/12/01 [Refereed][Not invited]
   

  Al-rich cubic (c-) AlxTi1-xN (x μ 0.8) coating comprising self-organised c-Al(Ti)N/c-Ti(Al)N nanolamellae was prepared in a previous study by low-pressure chemical vapour deposition (LP-CVD) using an AlCl3-TiCl4-NH3-Ar-H2 precursor system. In the present study, we investigated the effects of isothermal annealing at 800 to 1200°C for 1 to 10 h on the crystal structure, microstructure, and hardness of the coating, and compared them to those of a monolithic c-AlxTi1-xN (x μ 0.6) coatings prepared by arc-evaporated physical vapour deposition (PVD). The X-ray diffraction patterns indicated high phase stability of the former coating up to 1200°C after 1 h. High-resolution transmission electron microscopy revealed that the nanolamellae in c-AlxTi1-xN (x μ 0.8) coating remained stable after post-annealing at 900°C for 5 h. The spontaneously formed coherent nanostructure suppressed diffusion in this coating, and the spinodal decomposition and hexagonal phase formation were thus shifted to higher temperatures. Consequently, age hardening in LP-CVD c-AlxTi1-xN (x μ 0.8) helped to maintain its hardness at up to 1100°C after 10 h. The improved thermal stability and hardness at elevated temperature of the Al-rich c-AlxTi1-xN coating by LP-CVD led to a significant improvement in the cutting tool life, by factors of 2 and 10 compared to state-of-the-art CVD-and PVD-coated inserts, respectively. These improvements in thermal stability and elevated hardness in c-AlxTi1-xN (x μ 0.8) coating prepared via LP-CVD process could remarkably enhance tool life for dry and high-speed cutting applications.
• Synthesis of rutile-type solid solution Ni1−xCoxTi(Nb1−yTay)2O8 (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) and its optical property

  Nobuhiro Kumada, Narumi Koike, Kousuke Nakanome, Sayaka Yanagida, Takahiro Takei, Akira Miura, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa

  Journal of Asian Ceramic Societies 5 (3) 284 - 289 2187-0764 2017/09/01 [Refereed][Not invited]
   

  Rutile-type solid solutions Ni1−xCoxTi(Nb1−yTay)2O8 (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) were prepared by high temperature solid state reaction. The solid solutions of noibates (y = 0) had a rutile-type structure and those of tantalates (y = 1.0) had a trirutile-type one. The trirutile-type structure appeared in the composition of y ≥ 0.4. The crystal structures of these solid solutions for niobates and tantalates were refined by using synchrotron X-ray powder diffraction data and the R-factors were Rwp = 1.76–1.92% and Rp = 1.13–1.19% for niobates and Rwp = 10.3–12.2% and Rp = 6.78–9.14% for tantalates. Their lattice parameters for noibates ranges from a = 4.69413(2) to 4.70411(2) Å and c = 3.02187(1) to 3.03242(1) Å and those for tantalates ranges from a = 4.6946(2) to 4.7065(2) Å and c = 9.0829(3) to 9.1164(4) Å. The optical band gap for these solid solutions ranged from 1.63 to 2.50 eV and only NiTiTa2O8 exhibited photocatalytic activity for phenol decomposition under UV light irradiation. The dielectric constants for four end members, NiTiNb2O8, CoTiNb2O8, NiTiTa2O8 and CoTiTa2O8 were 25–75 in the temperature range from room temperature to 300 °C.
• Prediction of Ternary Liquidus Temperatures by Statistical Modeling of Binary and Ternary Ag-Al-Sn-Zn Systems.

  Akira Miura, Tsukasa Hokimoto, Masanori Nagao, Takashi Yanase, Toshihiro Shimada, Kiyoharu Tadanaga

  ACS omega 2 (8) 5271 - 5282 2017/08/31 [Refereed][Not invited]
   

  The relationship of liquidus temperatures among six binary and four ternary phases in a Ag-Al-Sn-Zn system was analyzed by means of statistical modeling. Four statistical models to predict changes in the liquidus temperatures in Ag-Al-Sn-Zn were proposed on the basis of different hypotheses derived from macroscopic and microscopic standpoints. The results of interpolation tests to evaluate the prediction accuracies of the ternary liquidus temperatures suggested that the multivariate regression model based on binary liquidus temperatures, interactive binary liquidus temperatures, and products of atomic ratios was found to be the most effective among the four models. It was numerically shown that the prediction accuracies of the liquidus temperatures in local ternary systems of Ag-Al-Sn-Zn can be improved further by using the models identified in their neighboring systems. Finally, the possibility to extract the general trend and the abnormal combination of elements for the prediction of liquidus temperatures was discussed on the basis of the statistical framework we considered.
• Crystal structure, site selectivity, and electronic structure of layered chalcogenide LaOBiPbS3

  Y. Mizuguchi, Y. Hijikata, T. Abe, C. Moriyoshi, Y. Kuroiwa, Y. Goto, A. Miura, S. Lee, S. Torii, T. Kamiyama, C. H. Lee, M. Ochi, K. Kuroki

  EPL 119 (2) 26002  0295-5075 2017/07 [Refereed][Not invited]
   

  We have investigated the crystal structure of LaOBiPbS3 using neutron diffraction and synchrotron X-ray diffraction. From structural refinements, we found that the two metal sites, occupied by Bi and Pb, were differently surrounded by the sulfur atoms. Calculated bond valence sum suggested that one metal site was nearly trivalent and the other was nearly divalent. Neutron diffraction also revealed site selectivity of Bi and Pb in the LaOBiPbS3 structure. These results suggested that the crystal structure of LaOBiPbS3 can be regarded as alternate stacks of the rock-salt-type Pb-rich sulfide layers and the LaOBiS2-type Bi-rich layers. From band calculations for an ideal (LaOBiS2)(PbS) system, we found that the S bands of the PbS layer were hybridized with the Bi bands of the BiS plane at around the Fermi energy, which resulted in the electronic characteristics different from that of LaOBiS2. Stacking the rock-salt type sulfide (chalcogenide) layers and the BiS2-based layered structure could be a new strategy to exploration of new BiS2-based layered compounds, exotic two-dimensional electronic states, or novel functionality. Copyright (C) EPLA, 2017
• Synthesis, structure and photocatalytic activity of layered LaOInS2

  Akira Miura, Takayoshi Oshima, Kazuhiko Maeda, Yoshikazu Mizuguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yu Meng, Xiao-Dong Wen, Masanori Nagao, Mikio Higuchia, Kiyoharu Tadanaga

  JOURNAL OF MATERIALS CHEMISTRY A 5 (27) 14270 - 14277 2050-7488 2017/07 [Refereed][Not invited]
   

  Indium oxychalcogenides would be attractive semiconductors considering the practical use of indium oxides and sulfides such as indium-tin oxides (ITO) and copper-indium-gallium diselenides (CIGS). In this work, a novel layered indium oxysulfide, LaOInS2, was synthesized by a metathesis reaction between LaOCl and NaInS2. Synchrotron X-ray diffraction showed that LaOInS2 consisted of alternately stacked rocksalt-type In-S and PbO-type La-O layers. The InS6 octahedron had split In sites with abnormally large anisotropic atomic displacement factors. LaOInS2 was found to be a direct semiconductor. Density functional theory calculations exhibited well-dispersed bands composed of In 5s/5p and S 3p/O 2p orbitals with a band gap of similar to 2.4 eV, which was close to the experimental value estimated by optical absorption (2.64 eV). Under visible light irradiation this visible-light absorption, LaOInS2 exhibited photocatalytic activity for H-2 and O-2 evolution from water with the aid of Pt and IrO2 cocatalysts, respectively.
• Intrinsic Phase Diagram of Superconductivity in the BiCh(2)-Based System Without In-Plane Disorder

  Kouhei Nagasaka, Atsuhiro Nishida, Rajveer Jha, Joe Kajitani, Osuke Miura, Ryuji Higashinaka, Tatsuma D. Matsuda, Yuji Aoki, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Hidetomo Usui, Kazuhiko Kuroki, Yoshikazu Mizuguchi

  JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 86 (7) 074701  0031-9015 2017/07 [Refereed][Not invited]
   

  We have investigated the crystal structure and physical properties of LaO1-xFxBiSSe to reveal the intrinsic superconductivity phase diagram of the BiCh2-based layered compound family. From synchrotron X-ray diffraction and Rietveld refinements with anisotropic displacement parameters, we clearly found that the in-plane disorder in the BiSSe layer was fully suppressed for all x. In LaO1-xFxBiSSe, metallic conductivity and superconductivity are suddenly induced by electron doping even at x = 0.05 and 0.1 with a monoclinic structure. In addition, x (F concentration) dependence of the transition temperature (T-c) for x = 0.2 -0.5 with a tetragonal structure shows an anomalously flat phase diagram. With these experimental facts, we have proposed the intrinsic phase diagram of the ideal BiCh(2)-based superconductors with less in-plane disorder.
• FePS3 electrodes in all-solid-state lithium secondary batteries using sulfide-based solid electrolytes

  Yuta Fujii, Akira Miura, Nataly Carolina Rosero-Navarro, Mikio Higuchi, Kiyoharu Tadanaga

  ELECTROCHIMICA ACTA 241 (1) 370 - 374 0013-4686 2017/07 [Refereed][Not invited]
   

  In bulk-type all-solid-state lithium batteries with sulfide-based solid electrolytes, composite electrodes, in which an active material, a solid electrolyte, and a conductive additive are mixed, have been used to enhance lithium-ion diffusion and electronic conductivity. However, the addition of electrolytes and electron-conductive additives to the composite electrodes decreases the amount of active materials in the batteries. In the present study, FePS3 was employed as the electrode in an all-solid-state lithium secondary battery, without mixing the solid electrolytes and conductive additives. The all-solid-state cell using the FePS3 electrode exhibited reversible charge-discharge behavior for more than 30 cycles under a constant current density of 0.13 mA cm (2) at room temperature. The discharge capacity of the cell was 107 mAh g (1) at the 30th cycle. This behavior was comparable to that of a cell with an electrode including a solid electrolyte and/or a conductive additive, indicating that the FePS3 electrode had sufficient paths of lithium ions and of electron conduction. These results suggest that FePS3 is an attractive iron-based electrode for an all-solid-state battery using a sulfide-based solid electrolyte. (C) 2017 Elsevier Ltd. All rights reserved.
• Synthesis of LaO0.5F0.5BiS2 nanosheets by ultrasonification

  Akira Miura, Satoshi Ishii, Masanori Nagao, Ryo Matsumoto, Yoshihiko Takano, Satoshi Watauchi, Isao Tanaka, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  Journal of Asian Ceramic Societies 5 (2) 183 - 185 2187-0764 2017/06/01 [Refereed][Not invited]
   

  LaO0.5F0.5BiS2 nanosheets were produced by ultrasonification. A slightly reddish colloidal suspension was obtained by ultrasonification of LaO0.5F0.5BiS2 powder in ethanol. Transmission electron microscope (TEM) images of the dried suspension indicated the nanosheet morphology of LaO0.5F0.5BiS2, and the electron diffraction spots indicated 4-fold symmetry. The thickness of the sheets was 2–6 nm, which corresponded to 2–4 unit cells of the c-axis of LaO0.5F0.5BiS2.
• Effect of the binder content on the electrochemical performance of composite cathode using Li6PS5Cl precursor solution in an all-solid-state lithium battery

  Nataly Carolina Rosero-Navarro, Taiki Kinoshita, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga

  IONICS 23 (6) 1619 - 1624 0947-7047 2017/06 [Refereed][Not invited]
   

  All-solid-state batteries with cathode composites containing high concentration of active materials are required to achieve higher energy densities. Here, a composite cathode containing up to 89 wt% of high-voltage cathode active material (LiNi1/3Mn1/3Co1/3O2) was prepared by covering this with a solution-derived solid electrolyte (argyrodite, Li6PS5Cl) and the incorporation of different content binder (ethyl cellulose). All-solid-state batteries were fabricated using 80Li(2)Sa (TM) 20P(2)S(5) (mol%) glass and indium metal as a solid electrolyte and anode, respectively. The all-solid-state battery with a composite cathode containing 0.5 wt% of ethyl cellulose showed an initial discharge capacity of 45 mAhg(-1) at 25 A degrees C and maintained 91.7% of the discharge capacity after ten cycles, around 30% higher than that obtained for the battery with the composite cathode without a binder.
• Bi Substitution Effects on Superconductivity of Valence-Skip Superconductor AgSnSe2

  Yudai Hijikata, Atsuhiro Nishida, Kohei Nagasaka, Osuke Miura, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshikazu Mizuguchi

  JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 86 (5) 054711  0031-9015 2017/05 [Refereed][Not invited]
   

  We have synthesized AgSn1-xBixSe2 polycrystalline samples to investigate the effect of partial substitution of mixed-valence Sn by Bi3+ to the superconductivity of the valence-skip superconductor AgSnSe2. The Bi-substituted AgSn1-x-BixSe2 were obtained up to x = 0.2, but an insulating phase Ag2SnBi2Se5 with a NaCl-type structure showed up above x = 0.3. The superconducting transition temperature increased from 4.5K (x = 0) to 5.0K (x = 0.1) by Bi substitution. The enhancement of superconductivity by the suppression of the valence-skip states of Sn suggests that the valence-skip states of Sn are not positively linked to the pairing mechanisms of superconductivity in the AgSnSe2 system.
• A layered wide-gap oxyhalide semiconductor with an infinite ZnO2 square planar sheet: Sr2ZnO2Cl2

  Yu Su, Yoshihiro Tsujimoto, Akira Miura, Shinichiro Asai, Maxim Avdeev, Hiraku Ogino, Miho Ako, Alexei A. Belik, Takatsugu Masuda, Tetsuo Uchikoshi, Kazunari Yamaura

  CHEMICAL COMMUNICATIONS 53 (27) 3826 - 3829 1359-7345 2017/04 [Refereed][Not invited]
   

  A new square-planar zinc oxyhalide, Sr2ZnO2Cl2, was successfully synthesized using a high-pressure method. Absorption spectroscopy revealed an indirect band gap of 3.66 eV. Electronic structure calculations indicated a strong hybridization between Zn 3d(x2-y2) and O 2p orbitals, which is distinct from tetrahedrally coordinated ZnO.
• Hydrothermal Synthesis, Structure, and Superconductivity of Simple Cubic Perovskite (Ba0.62K0.38)(Bi0.92Mg0.08)O-3 with T-c similar to 30 K

  Mirza H. K. Rubel, Takahiro Takei, Nobuhiro Kumada, M. Mozahar Ali, Akira Miura, Kiyoharu Tadanaga, Kengo Oka, Masaki Azuma, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa

  INORGANIC CHEMISTRY 56 (6) 3174 - 3181 0020-1669 2017/03 [Refereed][Not invited]
   

  We have synthesized a new superconducting perovskite bismuth oxide by a facile hydrothermal route at 220 degrees C. The choice of starting materials, their mixing ratios, and the hydrothermal reaction temperature was crucial for obtaining products with superior superconducting properties. The structure of the powder sample was investigated using laboratory X-ray diffraction, high -resolution synchrotron X-ray diffraction (SXRD) data, and electron diffraction (ED) patterns [transmission electron microscopy (TEM) analysis]. The refinement of SXRD data confirmed a simple perovskitetype structure with a cubic cell of a = 4.27864(2) angstrom [space group Pm3m (No. 221)]. Elemental analysis detected magnesium in the final products, and a refinement based on SXRD and inductively coupled plasma data yielded an ideal undistorted simple cubic perovskite-type structure, with the chemical composition (Ba0.62K0.38)(Bi0.92Mg0.08)O-3. ED patterns also confirmed the simple cubic perovskite structure; the cube -shaped microstructures and compositional homogeneity on the nanoscale were verified by scanning electron microscopy and TEM analyses, respectively. The fabricated compound exhibited a large shielding volume fraction of about 98% with a maximum T-c(mag) of similar to 30 K, which was supported by the measured bismuth valence as well. Its electrical resistivity dropped at similar to 21 K, and zero resistivity was observed below 7 K The compound underwent thermal decomposition above 400 degrees C. Finally, the calculated band structure showed a metallic behavior for this hydrothermally synthesized bismuth oxide.
• Synthesis of mesoporous silica-phosphate hybrids and their adsorption competency for rare earth metal cations

  Fumitake Okabe, Chinami Mochizuki, Takahiro Takei, Sayaka Yanagida, Akira Miura, Nobuhiro Kumada

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 125 (10) 732 - 736 1882-0743 2017 [Refereed][Not invited]
   

  Mesoporous silica-phosphate hybrids were successfully prepared by three processes: hybridization post synthesis by H3PO4, hybridizations during synthesis by Na2HPO4 and by PO(OC2H5). X-ray diffraction patterns confirm that the hexagonal pore structure was maintained after the hybridization process. The maximum phosphate amount was 2.9 mol% in the sample prepared by hybridization during synthesis from Na2SiO3 and PO(OC2H5)(3). The specific surface area showed a large value of approximately 1000 m(2)/g despite the hybridization. The Si-O-P bonds were confirmed by nuclear magnetic resonance and X-ray photoelectron spectroscopy. The maximum adsorption amount of rare earth metal cations into the hybrid was approximately 70% of the initial concentration (50 mg/L) for each rare earth metal cation in coexistence with 13 rare earth metal cations. (C) 2017 The Ceramic Society of Japan. All rights reserved.
• Instantaneous preparation of high lithium-ion conducting sulfide solid electrolyte Li7P3S11 by a liquid phase process

  Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga

  RSC ADVANCES 7 (73) 46499 - 46504 2046-2069 2017 [Refereed][Not invited]
   

  A solid electrolyte with a small particle size, good mechanical properties and high ionic conductivity is required to achieve high energy and power density in the all-solid-state battery. Here, we report an instantaneous preparation of high lithium-ion conducting sulfide solid electrolyte Li7P3S11 by a simple procedure involving a liquid phase process under ultrasonic irradiation and low thermal treatment at 220 degrees C. A short reaction time of 30 min was enough to produce the formation of PS43- units. Subsequent drying and heating processes led to the precipitation of the Li7P3S11 phase with a particle size below 500 nm, achieving high ionic conductivity of 1.0 x 10(-3) S cm(-1) at 22 degrees C and a low activation energy of 12.8 kJ mol(-1).
• Low-temperature synthesis and rational design of nitrides and oxynitrides for novel functional material development

  Akira Miura

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 125 (7) 552 - 558 1882-0743 2017 [Refereed][Invited]
   

  Nitrides and oxynitrides exhibit great potential for novel material development, since their electronic structures can be controlled by tuning the amounts of air-abundant nitrogen and oxygen elements therein. However, the above control methods still need to be developed, and the crystal and electronic structures of the produced nitrides/oxynitrides need to be understood. Herein, I summarize the recent progress in nitride and oxynitride synthesis, highlighting novel low-temperature nitridation of oxides by molten NaNH2, and attempt to rationalize the crystal and electronic structures of nitride and oxynitrides. Moreover, I describe how the catalytic activity of manganese oxynitrides in the oxygen reduction reaction can be enhanced by tuning their nitrogen content and thus their electronic structures. (C)2017 The Ceramic Society of Japan. All rights reserved.
• Hydrothermal synthesis and crystal structure of a new lithium copper bismuth oxide, LiCuBiO4

  Nobuhiro Kumada, Ayumi Nakamura, Akira Miura, Takahiro Takei, Masaki Azuma, Hajime Yamamoto, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa

  JOURNAL OF SOLID STATE CHEMISTRY 245 30 - 33 0022-4596 2017/01 [Refereed][Not invited]
   

  A new lithium copper bismuth oxide, LiCuBiO4 was prepared by hydrothermal reaction using NaBiO3.1.4H(2)O. The crystal structural model of this compound was refined by using synchrotron X-ray powder diffraction data. This bismuthate has the LiCuSbO4 related structure with the orthorhombic cell (Space group: Pnma) of a=10.9096(9), b=5.8113(5) and c=5.0073(4) angstrom, and the final R-factors were R-factors were R-wp=4.84 and R-p=3.58%. This compound is the first example of a lithium copper bismuthate containing Bi5+ An antiferromagnetic ordering of Cu2+ moment was observed at 6 K.
• Deposition and Analysis of Al-Rich c-AlxTi1-xN Coating with Preferred Orientation

  Anongsack Paseuth, Kazuo Yamagata, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga

  JOURNAL OF THE AMERICAN CERAMIC SOCIETY 100 (1) 343 - 353 0002-7820 2017/01 [Refereed][Not invited]
   

  Metastable c-AlxT1-xN is an important and well-established hard coating in the tool industry. To improve the mechanical and thermal properties, Al-rich c-AlxTi1-xN coatings with controllable preferred crystal orientations were fabricated via low-pressure chemical vapor deposition (LP-CVD) in an industrial plant, using an AlCl3-TiCl4-NH3-Ar-H-2 precursor system. The c-AlxTi1-xN coatings with (100)- and (111)-preferred orientations and average x values of 0.82 and 0.73, respectively, comprised c-Al(Ti)N/c-Ti(Al)N nanolamellae with average compositions of c-Al0.9Ti0.1N/c-Al0.6Ti0.4N and c-Al0.80Ti0.20N/c-Al0.50Ti0.50N; the average lamellar periods were 7.7 and 4.5 nm, respectively. High-resolution transmission electron microscopy indicated that the c-Al(Ti)N/c-Ti(Al)N nanolamellae were modulated along the < 100 > direction, implying coherent spinodal decomposition of c-AlxTi1-xN in the as-deposited state. The hardness of the c-AlxTi1-xN coatings varied from 33 to 36 GPa, depending on the (100)- or (111)-preferred orientation. Residual stress measurements in the as-deposited state showed tensile stress values of 1.8 and 4.6 GPa for the (100)- and (111)-oriented c-AlxT1-xN coatings, respectively. This stress may be generated by the difference in the thermal expansion coefficient of the c-AlxT1-xN coating and the carbide substrate and by coherency stress in the c-Al(Ti)N/c-Ti(Al)N nanolamellae. In situ high-temperature X-Ray diffraction results revealed high thermal stability up to 1000 degrees C.
• Effect of Sintering Additives on Relative Density and Li-ion Conductivity of Nb-Doped Li7La3ZrO12 Solid Electrolyte

  Nataly Carolina Rosero-Navarro, Taira Yamashita, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga

  JOURNAL OF THE AMERICAN CERAMIC SOCIETY 100 (1) 276 - 285 0002-7820 2017/01 [Refereed][Not invited]
   

  Lithium ion conductors with garnet-type structure are promising candidates for applications in all solid-state lithium ion batteries, because these materials present a high chemical stability against Li metal and a rather high Li+ conductivity (10(-3)-10(-4)S/cm). Producing densified Li-ion conductors by lowering sintering temperature is an important issue, which can achieve high Li conductivity in garnet oxide by preventing the evaporation of lithium and a good Li-ion conduction in grain boundary between garnet oxides. In this study, we concentrate on the use of sintering additives to enhance densification and microstructure of Li7La3ZrNbO12 at sintering temperature of 900 degrees C. Glasses in the LiO2-B2O3-SiO2-CaO-Al2O3 (LBSCA) and BaO-B2O3-SiO2-CaO-Al2O3 (BBSCA) system with low softening temperature (<700 degrees C) were used to modify the grain-boundary resistance during sintering process. Lithium compounds with low melting point (<850 degrees C) such as LiF, Li2CO3, and LiOH were also studied to improve the rearrangement of grains during the initial and middle stages of sintering. Among these sintering additives, LBSCA and BBSCA were proved to be better sintering additives at reducing the porosity of the pellets and improving connectivity between the grains. Glass additives produced relative densities of 85-92%, whereas those of lithium compounds were 62-77%. Li7La3ZrNbO12 sintered with 4 wt% of LBSCA at 900 degrees C for 10h achieved a rather high relative density of 85% and total Li-ion conductivity of 0.8x10(-4)S/cm at room temperature (30 degrees C).
• Optimization of Al2O3 and Li3BO3 Content as Sintering Additives of Li7-xLa2.95Ca0.05ZrTaO12 at Low Temperature

  Nataly Carolina Rosero-Navarro, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga

  JOURNAL OF ELECTRONIC MATERIALS 46 (1) 497 - 501 0361-5235 2017/01 [Refereed][Not invited]
   

  Simultaneous effect of Al2O3 and Li3BO3 additions on sintering behavior and Li-ion conductivity of Li7-xLa2.95Ca0.05ZrTaO12 (LLCZT) garnet electrolyte sintered at 900 degrees C (10 h) is evaluated. The crystal phase and microstructure of the different composites were evaluated by x-ray diffraction and scanning electron microscopy (SEM), respectively. Electrical properties of the composites with high relative densities (95%) were examined by impedance spectroscopy. The cubic phase was formed for LLCZT sintered with 0-0.21 mol of Al2O3 and 0.70 mol-0.80 mol of Li3BO3. The excess of Al2O3 (0.22 mol) led to the formation of secondary phases. SEM observation revealed the good interconnection between LLCZT grains and the distribution of the glassy phase formed by Li3BO3 and Al2O3. Effective combination of 0.21 mol of Al2O3 and 0.80 mol of Li3BO3 produced denser material with high relative density of 95% and high Li-ion conduction of 1 x 10(-4) S/cm at 32 degrees C.
• Superconductivity in CeOBiS2 with cerium valence fluctuation

  Masanori Nagao, Akira Miura, Ikuo Ueta, Satoshi Watauchi, Isao Tanaka

  SOLID STATE COMMUNICATIONS 245 11 - 14 0038-1098 2016/11 [Refereed][Not invited]
   

  Resistivities of single-crystalline as well as poly-crystalline samples of CeOBiS2 without fluorine doping were measured at temperatures down to 0.13 K, and were compared with those of poly-crystalline LaOBiS2 and PrOBiS2. Both poly-crystalline and single-crystalline CeOBiS2 exhibited zero resistivity below 1.2 K while poly-crystalline LaOBiS2 and PrOBiS2 did not show zero resistivity down to 0.13 K. Superconducting transition temperature of CeOBiS2 was reduced by increasing the applied current density. The superconductivity of CeOBiS2 without chemical doping is likely triggered by the carriers induced by the valence fluctuation between Ce3+ and Ce4+. (C) 2016 Elsevier Ltd. All rights reserved.
• Adsorption Behavior of Rare Earth Metal Cations in the Interlayer Space of gamma-ZrP

  Takahiro Takei, Kiyoaki Iidzuka, Akira Miura, Sayaka Yanagida, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa

  LANGMUIR 32 (39) 9993 - 9999 0743-7463 2016/10 [Refereed][Not invited]
   

  Adsorption competencies of rare earth metal cations in gamma-zirconium phosphate were examined by ICP, synchrotron X-ray diffraction (SXRD), and ab initio simulation: The adsorption amounts are around 0.06-0.10 per zirconium phosphate. From the SXRD patterns of the adsorbed samples, the basal spacing estimated by c sin beta increased linearly with an increasing ionic radius of rare earth metal cation, though a and b lattice constants show no change. These SXRD patterns Can be classified into four groups that have different super lattices. The four superlattices have multiplicities of x131, x241, and x221 for the xabe axis, and the location of the rare earth metal cation in the original unit cell changes depending on the superlattice cell. In the x131 superlattice, Yb and Et occupied the site near the zirconium phosphate layer, though La and Ce in the x221 superlattice remained in the center position between the phosphate sheet. For the ab initio simulation of gamma-ZrP with the typical rare earth metal cations (Tb, Eu, Dy, and La), the results of simulation show a similar tendency of the position estimated by SXRD refinements.
• Discovery of the Pt-Based Superconductor LaPt5As

  Masaya Fujioka, Manabu Ishimaru, Taizo Shibuya, Yoichi Kamihara, Chihiro Tabata, Hiroshi Arnitsuka, Akira Miura, Masashi Tanaka, Yoshihiko Takano, Hideo Kaiju, Junji Nishii

  JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 138 (31) 9927 - 9934 0002-7863 2016/08 [Refereed][Not invited]
   

  A novel superconductor, LaPt5As, which exhibits a new crystal structure was discovered by high-pressure synthesis using a Kawai-type apparatus. A superconducting transition temperature was observed at 2.6 K. Depending on the sintering pressure, LaPt5As has superconducting and non superconducting phases with different crystal structures. A sintering pressure of around 10 GPa is effective to form single-phase superconducting LaPt5As. This material has a very unique crystal structure with an extremely long c lattice parameter of over 60 A and corner-sharing tetrahedrons composed of network like Pt layers. Density functional theory calculations have suggested that the superconducting current flows through these Pt layers. Also, this unique layered structure characteristic of LaPt5As is thought to play a key role in the emergence of superconductivity. Furthermore, due to a stacking structure which makes up layers, various structural modifications for the LaPt5As family are conceivable. Since such a high-pressure synthesis using a Kawai-type apparatus is not common in the field of materials science, there is large room for further exploration of unknown phases which are induced by high pressure in various materials.
• Nitrogen-Rich Manganese Oxynitrides with Enhanced Catalytic Activity in the Oxygen Reduction Reaction

  Akira Miura, Carolina Rosero-Navarro, Yuji Masubuchi, Mikio Higuchi, Shinichi Kikkawa, Kiyoharu Tadanaga

  ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 55 (28) 7963 - 7967 1433-7851 2016/07 [Refereed][Not invited]
   

  The catalytic activity of manganese oxynitrides in the oxygen reduction reaction (ORR) was investigated in alkaline solutions to clarify the effect of the incorporated nitrogen atoms on the ORR activity. These oxynitrides, with rock-saltlike structures with different nitrogen contents, were synthesized by reacting MnO, Mn2O3, or MnO2 with molten NaNH2 at 240-280 degrees C. The anion contents and the Mn valence states were determined by combustion analysis, powder X-ray diffraction, and X-ray absorption near-edge structure analysis. An increase in the nitrogen content of rock-salt-based manganese oxynitrides increases the valence of the manganese ions and reinforces the catalytic activity for the ORR in 1m KOH solution. Nearly single-electron occupancy of the antibonding e(g) states and highly covalent Mn-N bonding thus enhance the ORR activity of nitrogen-rich manganese oxynitrides.
• Valence of praseodymium in superconducting Pr(O,F)BiS2 single crystals

  Satoshi Ishii, Yasuaki Hongu, Akira Miura, Masanori Nagao

  APPLIED PHYSICS EXPRESS 9 (6) 63101  1882-0778 2016/06 [Refereed][Not invited]
   

  The praseodymium (Pr) valence in superconducting PrO1-xFxBiS2 (x = 0.13; 0.23) single crystals was evaluated by X-ray photoelectron spectroscopy. The Pr 3d core level is split into 3d(3/2) and 3d(5/2) levels. Both PrO1-xFxBiS2 and Pr2S3, which contain only Pr3+, showed 3d spectra at a lower binding energy than Pr6O11, which contains both Pr3+ and Pr4+. Neither PrO1-xFxBiS2 nor Pr2S3 showed the characteristic satellites of Pr4+ in 3d(5/2) spectra. The valence fluctuation between the Pr3+ and Pr4+ states was not confirmed, suggesting that Pr3+ is dominant in PrO1-xFxBiS2 (x = 0.13; 0.23) single crystals. (C) 2016 The Japan Society of Applied Physics
• High-Pressure Polymorph of NaBiO3

  Octavianti Naa, Nobuhiro Kumada, Akira Miura, Takahiro Takei, Masaki Azuma, Yoshihiro Kusano, Kengo Oka

  INORGANIC CHEMISTRY 55 (12) 5747 - 5749 0020-1669 2016/06 [Refereed][Not invited]
   

  A new high-pressure polymorph of NaBiO3 (hereafter beta-NaBiO3) was synthesized under the conditions of 6 GPa and 600 degrees C. The powder X-ray diffraction pattern of this new phase was indexed with a hexagonal cell of a = 9.968(1) angstrom and c = 3.2933(4) angstrom. Crystal structure refinement using synchrotron powder X-ray diffraction data led to R-WP = 8.53% and R-P = 5.55%, and the crystal structure was closely related with that of Ba2SrY6O12. No photocatalytic activity for phenol decomposition was observed under visible-light irradiation in spite of a good performance for its mother compound, NaBiO3. The optical band-gap energy of beta-NaBiO3 was narrower than that of NaBiO3, which was confirmed with density of states curves simulated by first-principles density functional theory calculation.
• Development of All-solid-state Lithium Secondary Batteries Using NiPS3 Electrode and Li2S-P2S5 Solid Electrolyte

  Yuta Fujii, Yusaku Suto, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga

  CHEMISTRY LETTERS 45 (6) 652 - 654 0366-7022 2016/06 [Refereed][Not invited]
   

  An all-solid-state lithium secondary battery using a NiPS3 electrode and a 80Li(2)S center dot 20P(2)S(5) glass solid electrolyte was fabricated, and the charge-discharge cycle performance of the corresponding all-solid-state cell was investigated. This all solid-state cell exhibited a stable reversible capacity of about 80 mAh g(-1) after 30 cycles with a current density of 64 mu A cm(-2) at room temperature. This suggests that NiPS3 has a potential as an electrode active material in all-solid-state lithium secondary batteries using Li2S-P2S5 solid electrolytes.
• Topotactic transformation of Ni-based layered double hydroxide film to layered metal oxide and hydroxide

  Takahiro Takei, Hiroki Fuse, Akira Miura, Nobuhiro Kumada

  APPLIED CLAY SCIENCE 124 236 - 242 0169-1317 2016/05 [Refereed][Not invited]
   

  Topotactic transformation of film-shaped samples comprising a layered double hydroxide (LDH) to a metal oxide phase was performed by a hydrothermal or heat treatment The degree of transformation was examined by X-ray photoelectron spectroscopy (XPS) and synchrotron X-ray diffraction (SXRD). The LDH film prepared as a raw material by a reflux process with urea was composed of plate-shaped particles that were partially perpendicular to the substrate. For the transformation, the LDH powder and film were treated hydrothermally at 90, 120, and 200 degrees C in a LiOH aqueous solution or heated to 400, 600, and 800 degrees C with a LiOH center dot H2O contact. The film shape and morphology of the LDH particles were retained after the hydrothermal treatment at 120 degrees C. XPS and SXRD confirmed that two types of LDH with different compositions, Ni:Co = 62:38 and 90:10, were formed in the as-prepared LDH. In the case of the sample treated hydrothermally, metal hydroxide with no intercalated anion within the interlayer space was observed and the metal oxyhydroxide formed with a ratio of approximately 15%. For the heated samples, the transformation to LiNi1-xCoxO2-related materials was carried out by heating to 600 or 800 degrees C. 2016 Elsevier B.V. All rights reserved.
• Structure, Superconductivity, and Magnetism of Ce(O,F)BiS2 Single Crystals (vol 15, pg 39, 2015)

  Akira Miura

  Crystal Growth & Design 16 (4) 2459  2016/04 [Refereed][Not invited]
  
• Compositional and temperature evolution of crystal structure of new thermoelectric compound LaOBiS2-xSex

  Y. Mizuguchi, A. Miura, A. Nishida, O. Miura, K. Tadanaga, N. Kumada, C. H. Lee, E. Magome, C. Moriyoshi, Y. Kuroiwa

  JOURNAL OF APPLIED PHYSICS 119 (15) 155103  0021-8979 2016/04 [Refereed][Not invited]
   

  We examined the crystal structure of the new thermoelectric material LaOBiS2-xSex, whose thermoelectric performance is enhanced by Se substitution, by using powder synchrotron X-ray diffraction and Rietveld refinement. The emergence of metallic conductivity and enhancement of the thermoelectric power factor of LaOBiS2-xSex can be explained with the higher in-plane chemical pressure caused by the increase of Se concentration at the in-plane Ch1 site (Ch = S, Se). High-temperature X-ray diffraction measurements for optimally substituted LaOBiSSe revealed anomalously large atomic displacement parameters (U-iso) for Bi and Ch atoms in the BiCh(2) conduction layers. The anisotropic analysis of the atomic displacement parameters (U-11 and U-33) for the in-plane Bi and Ch1 sites suggested that Bi atoms exhibit large atomic displacement along the c-axis direction above 300 K, which could be the origin of the low thermal conductivity in LaOBiSSe. The large Bi vibration along the c-axis direction could be related to in-plane rattling, which is a new strategy for attaining low thermal conductivity and phonon-glass-electron-crystal states. Published by AIP Publishing.
• Preparation of Li7La3(Zr2-x,Nb-x)O-12 (x=0-1.5) and Li3BO3/LiBO2 composites at low temperatures using a sol-gel process

  N. C. Rosero-Navarro, T. Yamashita, A. Miura, M. Higuchi, K. Tadanaga

  SOLID STATE IONICS 285 6 - 12 0167-2738 2016/02 [Refereed][Not invited]
   

  Li7La3(Zr-2 (-) Nb-x(x))O-12 (LLZNbO, x = 0-1.5) was prepared using sol-gel process at low temperatures. Additives (LiBO2 and Li3BO3) were used to improve the sintering of the ceramic electrolyte at low temperatures. XRD patterns of the calcined powder displayed the formation of cubic garnet phase between 600 and 700 degrees C in composition with higher Nb content (LLZNbO, x >= 0.5). The density of composites with additives sintered at 900 degrees C achieves 90%. In composites sintered with LiBO2, the presence of La2Zr2O7 was detected, whereas single cubic phase was obtained for the composites sintered with Li3BO3. The ion conductivity attained was 7 x 10(-5) S/cm at 30 degrees C using 6.5 wt% Li3BO3 (900 degrees C), representing enhancement by more than two orders of magnitude compared to the material without additives. Improvements of Li ion conductivity can be interpreted by the enhanced relative density as the result of the rearrangement of particles produced by adequate concentration of the additive. (C) 2015 Elsevier B.V. All rights reserved.
• Superconductivity in F-free CeOBiS2 with mixed valence

  Nagao Masanori, Miura Akira, Ueta Ikuo, Watauchi Satoshi, Tanaka Isao

  Meeting Abstracts of the Physical Society of Japan 一般社団法人 日本物理学会 71 2188 - 2188 2016 

  R(O,F)BiS_2_(R:La,Ce,Pr,Nd)は, OサイトにFが置換することで, キャリアが導入され, 超伝導になることが知られている. 本研究では, CeOBiS_2_においてF置換なしに超伝導が発現することを見出した. これは, 3+がメインであるCeの価数が一部4+になることで, キャリアが生成し, 超伝導が発現したのではないかと考えている.

• Thermoelectric properties and crystal structure of BiCh2-based layered compounds LaOBiS2-xSex

  Mizuguchi Yoshikazu, Nishida Atsuhiro, Miura Osuke, Miura Akira, Nishiate Hirotaka, Lee Chul-Ho

  Meeting Abstracts of the Physical Society of Japan 一般社団法人 日本物理学会 71 2195 - 2195 2016 

  BiCh_2_系層状化合物LaOBiS_2-x_Se_x_はSe置換量の増加により熱電特性が大幅に上昇し，高い無次元性能指数ZT = 0.36（650 K)を示す．本研究では熱電物性のSe濃度依存性を評価し，Se置換による熱電特性向上の起源を解明する．また，高温での結晶構造変化に基づき，低熱伝導度の起源を議論する．

• Hydrothermal Synthesis, Crystal Structure, and Superconductivity of a Double-Perovskite Bi Oxide

  Mirza H. K. Rubel, Takahiro Takei, Nobuhiro Kumada, M. Mozahar Ali, Akira Miura, Kiyoharu Tadanaga, Kengo Oka, Masaki Azuma, Masatomo Yashima, Kotaro Fujii, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, James R. Hester, Maxim Aydeev

  CHEMISTRY OF MATERIALS 28 (2) 459 - 465 0897-4756 2016/01 [Refereed][Not invited]
   

  Double-perovskite Bi oxides are a new series of superconducting materials, and their crystal structure and superconducting properties are under investigation. In this paper, we describe the synthesis and characterization of a new double-perovskite material that has an increased superconductive transition temperature of 31.5 K. The structure of the material was examined using powder neutron diffraction (ND), synchrotron X-ray diffraction (SXRD), and transmission electron microscopy (TEM). Rietveld refinement of the sample based on ND and SXRD data confirmed an A-site-ordered (K-1.00)(Ba-1.00)(3)(Bi0.89Na0.11)(4)O-12 double-perovskite-type structure with the space group Im (3) over barm (No. 229). This structural analysis revealed the incorporation of Na with Bi in the structure and a bent bond between (Na, Bi)-O-(Na, Bi). TEM analyses also confirmed a cubic double-perovskite structure. This hydrothermally synthesized compound exhibited a large shielding volume fraction, exceeding 100%, with onset of superconductivity at similar to 31.5 K. Its electrical resistivity dropped near onset at similar to 28 K, and zero resistivity was confirmed below 13 K. The calculated band structure revealed that the metallicity of the compound and the flatness of the conduction bands near the Fermi level (E-F) are important for the appearance of superconductivity.
• Structures and optical absorption of Bi2OS2 and LaOBiS2

  Akira Miura, Yoshikazu Mizuguchi, Takahiro Takei, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Kiyoharu Tadanaga

  SOLID STATE COMMUNICATIONS 227 19 - 22 0038-1098 2016/01 [Refereed][Not invited]
   

  The band gaps of isostructural Bi2OS2 and LaOBiS2 were examined using optical absorption and discussed with the band structures calculated based on the crystal structures determined, using synchrotron X-ray diffraction. The Bi 6p and S 3p orbitals in the Bi-S plane were computationally predicted to constitute the bands near the Fermi level. The optical reflectance spectra of Bi2OS2 and LaOBiS2 showed optical band gaps of similar to 1.0 eV, which were close to the computationally calculated direct band gaps of similar to 0.8 eV. Our results show that Bi2OS2 and LaOBiS2 are semiconductors containing direct band gaps of 0.8-1.0 eV, and they are suggested to be candidates for optoelectronic materials in the near-infrared region without highly toxic elements. (C) 2015 Elsevier Ltd. All rights reserved.
• Structural Difference in Superconductive and Nonsuperconductive Bi-S Planes within Bi4O4Bi2S4 Blocks

  Akira Miura, Yoshikazu Mizuguchi, Tsuyoshi Sugawara, Yongming Wang, Takahiro Takei, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Osuke Miura, Kiyoharu Tadanaga

  INORGANIC CHEMISTRY 54 (21) 10462 - 10467 0020-1669 2015/11 [Refereed][Not invited]
   

  The relationship between the structure and superconductivity of Bi4O4S3 powders synthesized by heating under ambient and high pressures was investigated using synchrotron X-ray diffraction, Raman spectroscopy, and transmission electron microscopy (TEM) observation. The Bi4O4S3 powders synthesized under ambient pressure exhibited a strong superconductivity (diamagnetic) signal and zero resistivity below similar to 4.5 K, while the Bi4O4S3 powder synthesized by the high-pressure method exhibited a low-intensity signal down to 2 K. Further annealing of the latter Bi4O4S3 powder under ambient pressure led to the development of a strong signal and zero resistivity. The crystal structures of all Bi4O4S3 phases consisted of Bi4O4Bi2S4 blocks including a Bi-S layer and anion(s) sandwiched between Bi4O4Bi2S4 blocks, but minor structural differences were detected. A comparison of the structures of the superconductive and nonsuperconductive Bi4O4S3 samples suggested that the superconductive Bi4O4S3 phases had slightly smaller lattice parameters. The average structures of the superconductive Bi4O4S3 phases were characterized by a slightly shorter and less bent BiS plane. Raman spectroscopy detected vibration of the S-O bonds, which can be attributed to sandwiched anion(s) such as SO42-. TEM observation showed stacking faults in the superconductive Bi4O4S3 phases, which indicated local fluctuation of the average structures. The observed superconductivity of Bi4O4S3 was discussed based on impurity phases, enhanced hybridization of the px and py orbitals of the Bi-S plane within Bi4O4Bi2S4 blocks, local fluctuation of the average structures, compositional deviation related to suspicious anion(s) sandwiched between Bi4O4Bi2S4 blocks, and the possibility of suppression of the charge-density-wave state by enriched carrier concentrations.
• In-plane chemical pressure essential for superconductivity in BiCh(2)-based (Ch: S, Se) layered structure

  Yoshikazu Mizuguchi, Akira Miura, Joe Kajitani, Takafumi Hiroi, Osuke Miura, Kiyoharu Tadanaga, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa

  SCIENTIFIC REPORTS 5 14968  2045-2322 2015/10 [Refereed][Not invited]
   

  BiCh(2)-based compounds (Ch: S, Se) are a new series of layered superconductors, and the mechanisms for the emergence of superconductivity in these materials have not yet been elucidated. In this study, we investigate the relationship between crystal structure and superconducting properties of the BiCh(2)-based superconductor family, specifically, optimally doped Ce1-xNdxO0.5F0.5BiS2 and LaO0.5F0.5Bi(S1-ySey)(2). We use powder synchrotron X-ray diffraction to determine the crystal structures. We show that the structure parameter essential for the emergence of bulk superconductivity in both systems is the in-plane chemical pressure, rather than Bi-Ch bond lengths or in-plane Ch-Bi-Ch bond angle. Furthermore, we show that the superconducting transition temperature for all REO(0.5)F(0.5)BiCh(2) superconductors can be determined from the in-plane chemical pressure.
• Hydrothermal synthesis and crystal structure analysis of two new cadmium bismuthates, CdBi2O6 and Cd0.37Bi0.63O1.79

  N. Kumada, A. Miura, T. Takei, S. Nishimoto, Y. Kameshima, M. Miyake, Y. Kuroiwa, C. Moriyoshi

  Journal of Asian Ceramic Societies 3 (3) 251 - 254 2187-0764 2015/09/01 [Refereed][Not invited]
   

  Two new cadmium bismuthates, CdBi2O6 and Cd0.37Bi0.63O1.79, were prepared by hydrothermal reaction using NaBiO3·nH2O as one of the starting compounds. The crystal structures of these compounds were refined by using synchrotron X-ray powder diffraction data. The former bismuthate has a MnSb2O6-type structure with a hexagonal cell (space group: P321) the cell parameters were a=9.3641(7) and c=4.9523(3)Å, and the final R-factors were Rwp=4.59% and Rp=3.04%. The latter bismuthate has a fluorite-type structure with a cubic cell (space group: Fm3-m) of a=5.4110(4)Å, and the final R-factors were Rwp=4.79% and Rp=3.57%. These new bismuthates exhibit no photocatalytic activity under visible light.
• Octahedral and trigonal-prismatic coordination preferences in Nb-, Mo-, Ta-, and W-based ABX(2) layered oxides, oxynitrides, and nitrides

  Akira Miura, Kiyoharu Tadanaga, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Takei Takahiro, Nobuhiro Kumada

  JOURNAL OF SOLID STATE CHEMISTRY 229 272 - 277 0022-4596 2015/09 [Refereed][Not invited]
   

  Crystallographic and electronic structures of Nb-, Mo-, Ta-, and W-based layered oxides, oxynitrides, and nitrides were analyzed to elucidate the structural relationship between layered oxides and nitrides consisting of octahedral and trigonal-prismatic layers. The electron density, as derived by synchrotron X-ray analysis of LiNbO2 and Ta5-x(O,N)(6), showed orbital overlaps between Nb-Nb and Ta-Ta metals in the trigonal layers. Computational calculations based on DFT exhibited that these overlaps stabilized these structures by lowering the hybridization states composed of the d(xy), d(x2-y2), and d(z2) orbitals below the Fermi level. Crystal structures and formation energies suggest that tuning the Fermi level through the substitutions and vacancies of the cation/anion sites determines the structural preferences of the coordination. The properties and syntheses of these compounds are briefly described. This study enhances the understanding of layered oxides, oxynitrides, and nitrides to further the development of new synthetic approaches, compounds, and applications. (C) 2015 Elsevier Inc. All rights reserved.
• Alkaline earth metal doped tin oxide as a novel oxygen storage material

  Qiang Dong, Shu Yin, Mizuki Yoshida, Xiaoyong Wu, Bin Liu, Akira Miura, Takahiro Takei, Nobuhiro Kumada, Tsugio Sato

  MATERIALS RESEARCH BULLETIN 69 116 - 119 0025-5408 2015/09 [Refereed][Not invited]
   

  Alkaline earth metal doped tin oxide (SnO2) hollow nanospheres with a diameter of 50 nm have been synthesized successfully via a facial solvothermal route in a very simple system composed of only ethanol, acetic acid, SnCl4 center dot 5H(2)O and A(NO3)(2)center dot xH(2)O (A = Mg, Ca, Sr, Ba). The synthesized undoped SnO2 and A-doped SnO2 hollow nanospheres were characterized by the oxygen storage capacity (OSC), X-ray diffraction, transmission electron microscopy and the Brunauer-Emmet-Teller (BET) technique. The OSC values of all samples were measured using thermogravimetric-differential thermal analysis. The incorporation of alkaline earth metal ion into tin oxide greatly enhanced the thermal stability and OSC. Especially, Ba-doped SnO2 hollow nanospheres calcined at 1000 degrees C for 20 h with a BET surface area of 61 m(2) g(-1) exhibited the considerably high OSC of 457 mu mol-O g(-1) and good thermal stability. Alkaline earth metal doped tin oxide has the potential to be a novel oxygen storage material. (C) 2014 Elsevier Ltd. All rights reserved.
• C-axis electrical resistivity of PrO1-aFaBiS2 single crystals

  Masanori Nagao, Akira Miura, Satoshi Watauchi, Yoshihiko Takano, Isao Tanaka

  JAPANESE JOURNAL OF APPLIED PHYSICS 54 (8) 83101  0021-4922 2015/08 [Refereed][Not invited]
   

  The high anisotropy in RO1-aFaBiS2 (R denotes a rare-earth element) superconductors demonstrates their potential use as intrinsic Josephson junctions, considering the weak coupling among BiS2-PrO(F)-BiS2 (superconducting-normal-superconducting) layers along the c-axis. We grew PrO1-aFaBiS2 single crystals using CsCl/KCl flux. The superconducting anisotropies of the grown single crystals were estimated to be approximately 40-50 from the effective mass model. The c-axis transport properties were characterized using single-crystal s-shaped intrinsic Josephson junctions with a focused ion beam. Along the c-axis, the crystals showed zero resistivity at 2.7 K and a critical current density of 1.33 x 10(3) A/cm(2) at 2.0 K. The current-voltage curve along the c-axis displayed hysteresis. The c-axis transport measurements under a magnetic field parallel to the ab-plane revealed a "lock-in" state due to the Josephson vortex flow, indicating that BiS2 superconductors are promising candidates for intrinsic Josephson junctions. (C) 2015 The Japan Society of Applied Physics
• Preparation and phase transformation of Ag or Bi ion-exchanged layered niobate perovskite and their photocatalytic properties

  Nan Xu, Takahiro Takei, Akira Miura, Nobuhiro Kumada

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 123 (1440) 690 - 694 1882-0743 2015/08 [Refereed][Not invited]
   

  Ag-intercalated and Bi-intercalated layered perovskite were fabricated by ion-exchanged process. The XRD and XPS confirm the phase transformation of the Ag-ion exchanged layered perovskite from Dion-Jacobson to Ruddlesden-Popper phase by heating at higher than 200 degrees C. In the case of Bi ion-exchange perovskite, the product remained Dion-Jacobson phase during the heat treatment. For the Ag-intercalated sample, Ruddlesden-Popper type photocatalyst by heating at 500 degrees C can degrade 20 ppm phenol solution to 6ppm in 3 h under Xe light, which has superior photocatalytic activity to Dion-Jacobson phase Ag0.67H0.33LaNb2O7. For the Bi-intercalated sample, Dion-Jacobson type photocatalyst can degrade phenol from 20 to 12 ppm in 3 h. From first principle DFT simulation, high photocatalytic activity may be due to the new Ag 4d, O 2p and Nb 4d hybridized band at the highest of the valence band for Ag-included, and to the new Bi 6p band at the lowest of the conduction band for Bi-included samples. (C) 2015 The Ceramic Society of Japan. All rights reserved.
• Study on the Effect of Pt Intercalation into Layered Niobate Perovskite for Photocatalytic Behavior

  Nan Xu, Takahiro Takei, Akira Miura, Nobuhiro Kumada, Ken-ichi Katsumata, Nobuhiro Matsushita, Kiyoshi Okada

  LANGMUIR 31 (27) 7660 - 7665 0743-7463 2015/07 [Refereed][Not invited]
   

  A novel photocatalyst consisting of an intercalated perovskite H1-2xPtxLaNb2O7 was fabricated by ion, exchange. Synchrotron X-ray diffraction and X-ray photoelectron spectroscopy results confirmed that Pt2+ exists within the interlayer space of the layered perovskite: H1-2xPtxLaNb2O7 composed of layered niobate perovskite. and intercalated Pt2+ completely degraded a 20 ppm phenol solution in 3 h under irradiation by Xe light, which exhibits photocatalytic activity superior to those of RbLaNb2O7, Pt-deposited RbLaNb2O7, and HLaNb2O7. From first-principles density functional theory simulation, high photocatalytic activity Of H1-2xPtxLaNb2O7 is attributed to the emergence of a new O 2p-Pt 5d hybridized band on top of the valence band.
• Hydrothermal synthesis of a new Bi-based (Ba0.82K0.18)(Bi0.53Pb0.47)O-3 superconductor

  Mirza H. K. Rubel, Takahiro Takei, Nobuhiro Kumada, M. M. Ali, Akira Miura, Kiyoharu Tadanaga, K. Oka, M. Azuma, E. Magomae, C. Moriyoshi, Y. Kuroiwa

  JOURNAL OF ALLOYS AND COMPOUNDS 634 (15) 208 - 214 0925-8388 2015/06 [Refereed][Not invited]
   

  A new type of bismuth-oxide-based superconductor was prepared by a hydrothermal reaction at 240 degrees C. The synchrotron X-ray powder diffraction pattern reveals a simple perovskite-type structure with a cubic cell of a = 4.28877(1) angstrom with space group Pm-(3) over barm. The chemical composition of this cubic perovskite oxide was formulated as (Ba0.82K0.18)(Bi0.53Pb0.47)O-3 after structural refinement using synchrotron X-ray powder diffraction and chemical analysis data. The cubic microstructure and compositional homogeneity were confirmed by scanning electron microscopy analysis. This compound exhibited a diamagnetic signal with a shielding volume fraction of similar to 64% with an onset of approximately 22.8 K. Its resistivity started to drop at similar to 15 K, and zero resistivity was observed below 4 K. The thermal decomposition of this simple perovskite structure started above 600 degrees C. Finally, the calculated band structure also exhibited metallic behavior at ambient conditions. (C) 2015 Elsevier B.V. All rights reserved.
• Uniaxial Chemical Pressure and Disorder Effects on Magnetic and Dielectric Properties of beta '-(BEDT-TTF)(2)(ICl2)(1-x)(AuCl2)(x)

  Naoki Yoneyama, Takahide Kurobe, Satoshi Iguchi, Akira Miura, Takahiro Takei, Nobuhiro Kumada, Takahiko Sasaki

  JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 84 (3) 84 - 3 0031-9015 2015/03 [Refereed][Not invited]
   

  We have studied the structural, magnetic, and dielectric properties of the dimer-Mott insulator beta'-(BEDT-TTF)(2)(ICl2)(1-x)(AuCl2)(x). The AuCl2 substitution for ICl2 decreases the lattice length in the interlayer direction, leading to uniaxial chemical pressure with a negligible effect on the intralayer donor stacking. The variation of the Neel temperature as a function of x is explained on the basis of chemical pressure accompanied by anion disorder, while the dielectric response does not indicate the effect of chemical pressure. This suggests that the charge degrees of freedom are attributed to the intralayer origin such as the charge fluctuation of donor molecules induced by an electric field.
• Growth of Cu(In,Ga)S-2 single crystals using CsCl flux

  Masanori Nagao, Akira Miura, Satoshi Watauchi, Takahiro Takei, Nobuhiro Kumada, Isao Tanaka

  JOURNAL OF CRYSTAL GROWTH 412 (15) 16 - 19 0022-0248 2015/02 [Refereed][Not invited]
   

  Single crystals of Cu(In,Ga)S-2 were successfully grown using CsCl flux in vacuum The grown single crystals were typically 3-4 mm with unshaped form. The Cu(In,Ga)S-2 single crystals with various Ga concentration were obtained by control of the Ga concentration in the starting materials. The optical band-gaps of obtained single crystals were estimated from the reflectance spectrum The optical band-gap changed between 142 and 240 eV at room temperature with dependence on the Ga concentration. (C) 2014 Elsevier B.V. All rights reserved.
• Development of alkaline fuel cells using hydroxide-ion conductive layered double hydroxides

  Kiyoharu Tadanaga, Kohei Igarashi, Takashi Kubota, Akira Miura, Mikio Higuchi

  ECS Transactions 69 (17) 385 - 389 1938-6737 2015 [Refereed][Not invited]
   

  Layered double hydroxides (LDHs) intercalated with CO3 2- show high hydroxide ion conductivity of the order of 10-3 S cm-1 under 80% relative humidity. In the present study, (Ni, Mn)-Al LDHs and (Ni, Mn)-Fe LDHs intercalated with CO32- were prepared. The conductivity of (Ni, Mn)-Al LDH and (Ni, Mn)-Fe LDH was higher than that of Ni-Al LDH or Ni-Fe LDH. These LDHs were applied to the catalyst layer in an alkaline fuel cell for the improvement of the oxygen reduction reaction (ORR) at the triple phase boundary (TPB) in the catalyst layer. The addition of LDHs to the catalyst layer increased the current for ORR, indicating that hydroxide ion conducting LDHs introduced OH- conducting paths and increased TPB region within the catalyst layer. Above all, the addition of (Ni, Mn)-Fe LDH to the catalyst layer more effectively increased the reduction current for ORR than the addition of (Ni, Mn)-Al LDHs or Ni-Fe LDH. H2-O2 fuel cells with Ni-Al or Mg-Al LDHs as an electrolyte and MnO2 as the cathode catalyst were fabricated. The H2-O2 fuel cells were confirmed to be operated.
• Structure, Superconductivity, and Magnetism of Ce(O,F)BiS2 Single Crystals

  Akira Miura, Masanori Nagao, Takahiro Takei, Satoshi Watauchi, Yoshikazu Mizuguchi, Yoshihiko Takano, Isao Tanaka, Nobuhiro Kumada

  CRYSTAL GROWTH & DESIGN 15 (1) 39 - 44 1528-7483 2015/01 [Refereed][Not invited]
   

  The crystal structures of Ce(O,F)BiS2 synthesized from starting materials with five different F contents were determined by single-crystal X-ray analysis. An increase in F content in the starting materials slightly increased F incorporation in the grown single crystals. The grown crystals with various F contents showed similar layered structures, but minor structural changes were observed with different conductive and magnetic properties. Crystals grown from higher F content were found to have a nearly flat Bi-S plane and elongated Ce-(O,F) bond, and showed superconductive transition below similar to 3 K and spontaneous magnetization below similar to 7 K. The calculated density of states based on this structural analysis predicted that hybridized Bi 6p-S 3p orbitals intersect the Fermi level and that Ce states are located near the Fermi level. The effect of structural change on superconductivity and long-range magnetic ordering has been discussed.
• Synthesis of Cu3N from CuO and NaNH2

  Akira Miura, Takahiro Takei, Nobuhiro Kumada

  Journal of Asian Ceramic Societies 2 (4) 326 - 328 2187-0764 2014/12/01 [Refereed][Not invited]
   

  We report on the low-temperature synthesis of submicron-sized Cu3N powder produced from CuO and NaNH2 powder mixture by heating at 150-190°C in a Teflon-sealed autoclave. The structure was the anti-RuO3 type with a lattice parameter of 0.3814(1) nm, and strong optical absorption was observed below ~1.9eV. This synthesis method has the potential of facile control of the reaction with less use of ammonia sources.
• Anodic hybridization of fluorinated layered perovskite nanosheet with polyaniline for electrochemical capacitor

  Takahiro Takei, Nanae Muraki, Nan Xu, Akira Miura, Nobuhiro Kumada

  COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 459 186 - 193 0927-7757 2014/10 [Refereed][Not invited]
   

  A layered perovskite was fluorinated by polytetrafluoroethylene (PTFE) and then exfoliated to prepare a solution of fluorinated-perovskite nanosheets. Dion-Jacobson-type layered perovskites, RbLaNb2O7 and KCa2Nb3O10, were prepared in solid-state reactions at 950 and 1100 degrees C, respectively. The perovskites were fluorinated using PTFE at 400 degrees C, upon which their color changed from white to gray or black and their electrical conductivity increased to the order of 10(-4)-10(-5) S/m. The tetrabutyl ammonium cations(TBA(+)) in each fluorinated layered perovskite were first intercalated by tetrabutylammonium hydroxide(TBAOH) in H2O and then exfoliated in an acetonitrile solution for electrodeposition. Aniline was added to the solution as a monomer and electrodeposition was carried out in the acetonitrile solution for formation of a hybrid film. X-ray diffraction patterns confirmed that the polyaniline molecules could be intercalated within the interlayer space. Despite the fluorination, the volumetric filling fractions of polyaniline in the interlayer space were around 0.4 and 0.2 for the respective samples from RbLaNb2O7 and KCa2Nb3O10. The electrochemical specific capacitances of the deposited hybrid films increased steeply from below 50 F/g to above 230-250 F/g owing to the fluorination. (C) 2014 Elsevier B.V. All rights reserved.
• Photocatalytic Activities of Layered Niobate Perovskite (A'An-1NbnO3n+1, A: Ca, La) with Substitution of Ti and W for Nb

  Xu, Nan, Takei, Takahiro, Miura, Akira, Kumada, Nobuhiro

  Journal of Ion Exchange 25 242 - 247 2014/08 [Refereed][Not invited]
  
• Preparation and photocatalytic properties of new calcium and lead bismuthates

  Nobuhiro Kumada, Nan Xu, Akira Miura, Takahiro Takei

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 122 (1426) 509 - 512 1882-0743 2014/06 [Refereed][Not invited]
   

  Two new pentavalent bismuthates, CaBi2O6-x center dot 1.1H(2)O and PbBi2O6-x center dot H2O were prepared from NaBiO3 center dot nH(2)O. Broadened X-ray powder diffraction patterns for both bismuthates were indexed to the hexagonal cell observed for PbSb2O6-type SrBi2O6. The lattice parameters were a = 0.555(1) and c = 0.530(1) nm for CaBi2O6-x center dot 1.1H(2)O and a = 0.5544(4) and c = 0.531(1) nm for PbBi2O6-x center dot H2O. At elevated temperatures, the Ca derivative decomposed to Ca3Bi8O15 and an unknown phase via the fluorite-type structure, whereas the Pb derivative changed to Pb1/3Bi2/3O4/3 via the fluorite-type (Pb1/3Bi2/3)O-1.4. Both Ca and Pb derivatives exhibited photocatalytic activity for the decomposition of phenol under visible light irradiation, although the adsorption of phenol was observed under dark conditions. The fluorite-type phases evolved from the Ca and Pb derivatives did not adsorb phenol under dark conditions, and their photocatalytic activities toward phenol decomposition under visible light were inferior to those of the parent compounds. (C) 2014 The Ceramic Society of Japan. All rights reserved.
• Superconducting Double Perovskite Bismuth Oxide Prepared by a Low-Temperature Hydrothermal Reaction

  Mirza H. K. Rubel, Akira Miura, Takahiro Takei, Nobuhiro Kumada, M. Mozahar Ali, Masanori Nagao, Satoshi Watauchi, Isao Tanaka, Kengo Oka, Masaki Azuma, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, A. K. M. Azharul Islam

  ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 53 (14) 3599 - 3603 1433-7851 2014/04 [Refereed][Not invited]
   

  Perovskite-type structures (ABO(3)) have received significant attention because of their crystallographic aspects and physical properties, but there has been no clear evidence of a superconductor with a double-perovskite-type structure, whose different elements occupy A and/or B sites in ordered ways. In this report, hydrothermal synthesis at 220 degrees C produced a new superconductor with an A-site-ordered double perovskite structure, (Na0.25K0.45)(Ba-1.00)(3)(Bi-1.00)(4)O-12, with a maximum T-c of about 27 K.
• Molten salt synthesis of spinel-type LiTi2O4

  Nobuhiro Kumada, Mirza Humaun Kabir Rubel, Akira Miura, Takahiro Takei

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 122 (1424) 307 - 309 1882-0743 2014/04 [Refereed][Not invited]
   

  Spinel-type LiTi2O4 was prepared directly by the reaction of lepidocrocite-type potassium titanate and molten LiCl at 750-850 degrees C in a stream of H-2 gas. The Li/Ti ratio in the spinel-type phase prepared at 850 degrees C was 0.54, and the lattice parameter and superconductive critical temperature T-c were alpha = 8.3935(2) angstrom and 12.3 K, respectively. The product at 750 degrees C exhibited no superconductive diamagnetism down to 2.5 K, and the product at 800 C showed weak superconductive diamagnetism at 10.5 K. The morphology of the particles prepared at 850 degrees C showed an irregular shape with a particle size of 1-10 mu m. (C) 2014 The Ceramic Society of Japan. All rights reserved.
• Crystal structures of LaO1-xFxBiS2 (x similar to 0.23, 0.46): Effect of F doping on distortion of Bi-S plane

  Akira Miura, Masanori Nagao, Takahiro Takei, Satoshi Watauchi, Isao Tanaka, Nobuhiro Kumada

  JOURNAL OF SOLID STATE CHEMISTRY 212 213 - 217 0022-4596 2014/04 [Refereed][Not invited]
   

  The crystal structures of superconducting LaO1-xFxBiS2 (x similar to 0.23, 0.46) were determined by single-crystal X-ray diffraction analysis. Their space group was P4/nmm. Distortion of the Bi-S plane changed when the F content was increased from 0.23 to 0.46, and a nearly flat Bi-S plane was formed at x-0.46. Computational calculations supported this effect of F doping on distortion of Bi-S plane. LaO1-xFxBiS2 with higher F contents were computationally predicted to be thermodynamically more unstable under ambient pressure. We discussed the bonding, conductivities, and synthetic routes of LaO1-xFxBiS2. (C) 2014 Elsevier Inc. All rights reserved.
• Crystal structures and ferromagnetism of FexWN2 (x similar to 0.74, 0.90) with defective iron triangular lattice

  Akira Miura, Takahiro Takei, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa

  JOURNAL OF ALLOYS AND COMPOUNDS 593 154 - 157 0925-8388 2014/04 [Refereed][Not invited]
   

  The crystal structures of FexWN2 (x similar to 0.74, 0.90) and their magnetic properties were investigated. The structural studies reveal the formation of ion defects with different concentrations in the two-dimensional iron triangular lattice by analyzing the synchrotron radiation X-ray diffraction data. The magnetic measurements demonstrate that the Fe0.74WN2 phase shows ferromagnetism at 300 K, while the less defective Fe0.90WN2 phase exhibits no ferromagnetism. A decrease of temperature to 5 K significantly suppresses the room-temperature ferromagnetism of the Fe0.74WN2 phase. We attribute the emergence of ferromagnetism in FexWN2 to the increases of defect concentration and thermal displacement in the iron triangular lattice. (C) 2014 Elsevier B.V. All rights reserved.
• Single-crystalline porous NiO nanosheets prepared from beta-Ni(OH)(2) nanosheets: Magnetic property and photocatalytic activity

  Qiang Dong, Shu Yin, Chongshen Guo, Xiaoyong Wu, Nobuhiro Kumada, Takahiro Takei, Akira Miura, Yoshinori Yonesaki, Tsugio Sato

  APPLIED CATALYSIS B-ENVIRONMENTAL 147 741 - 747 0926-3373 2014/04 [Refereed][Not invited]
   

  Nickel hydroxide (beta-Ni(OH)(2)) nanosheets with a diameter of 400 nm and a thickness of 20 nm were successfully synthesized by a template and surfactant-free solvothermal route in a very simple system composed of LiOH center dot H2O and Ni-naphthenate. Furthermore, porous nickel oxide (NiO) nanosheets were obtained by thermal decomposition of beta-Ni(OH)(2) nanosheets in air at 350-550 degrees C for 2 h. HRTEM and SAED results revealed that the microporous NiO nanosheets obtained at 350 degrees C were single-crystalline, and nitrogen adsorption-desorption measurements of the BET surface area and pore size of porous NiO nanosheets were 156 m(2) g(-1) and 1.7 nm, respectively. Moreover, mesoporous NiO nanosheets and macroporous NiO nanosheets could be selectively obtained by controlling thermal decomposition temperature. The formation mechanism of porous NiO nanosheets was discussed. The magnetic property and photocatalytic activity of the porous NiO nanosheets were also investigated. The porous NiO nanosheets showed enhanced photocatalytic activity for NO destruction. (C) 2013 Elsevier B.V. All rights reserved.
• Effect of PTFE additives on low-temperature nitridation of LiInO2 using NaNH2 flux

  A. Miura, T. Takei, N. Kumada

  J. Ceram. Soc. Jpn. 122 (1) 86 - 88 2014/01/01 [Refereed][Not invited]
  
• Growth and superconducting properties of F-substituted ROBiS2 (R=La, Ce, Nd) single crystals

  Masanori Nagao, Akira Miura, Satoshi Demura, Keita Deguchi, Satoshi Watauchi, Takahiro Takei, Yoshihiko Takano, Nobuhiro Kumada, Isao Tanaka

  SOLID STATE COMMUNICATIONS 178 (3) 33 - 36 0038-1098 2014/01 [Refereed][Not invited]
   

  F-substituted ROBiS2 (R=La, Ce, Nd) superconducting single crystals with different F concentrations were grown successfully using a CsCl/KCl flux. All crystals produced had a plate-like shape, with a well-developed ab-plane 1-2 mm in size. Electron probe microanalysis did not detect any Cs, K, or Cl flux components in the crystals. As-grown single crystals of F-substituted LaOBiS2 and CeOBiS2 exhibited superconductivity at about 3 K, whereas F-substituted NdOBiS2 was superconductive at approximately 5 K. The superconducting anisotropy of single crystal F-substituted LaOBiS2 and NdOBiS2 was estimated to be 30-45 according to the effective mass model, whereas the anisotropy for F-substituted CeOBiS2 single crystals was 13-21. The F-substituted CeOBiS2 single crystals exhibited a magnetic order around 7 K that apparently coexisted with superconductivity below approximately 3 K. (C) 2013 Elsevier Ltd. All rights reserved.
• Effect of Polytetrafluoroethylene additive on low-temperature synthesis of InN crystals via reaction of LiInO2 and NaNH2

  Akira Miura, Takahiro Takei, Nobuhiro Kumada

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 122 (1421) 86 - 88 1882-0743 2014/01 [Refereed][Not invited]
   

  We examined the effect of polymer polytetrafluoroethylene ( PTFE) additive on the growth of InN crystals by the nitridation of LiInO2 in NaNH2 flux at 240 degrees C. LiInO2 and NaNH2 powder were heated with/without PTFE pieces in a steel crucible located inside the PTFE-lined autoclave. The additive of PTFE pieces enhanced the decomposition of LiInO2 with the mass loss of these pieces and progressed the formation of InN and In(OH)(3) byproducts. SEM and TEM images of the products using PTFE additives showed the hexagonal InN crystals of similar to 1 mu m in size, and the optical bandgap of synthesized InN was estimated as similar to 2.03 eV. We presume that fluorine in PTFE additive subtracts Li from LiInO2 and enhances the growth of InN crystals. (C)2014 The Ceramic Society of Japan. All rights reserved.
• Crystal structures of a pentavalent bismuthate, SrBi2O6 and a lead bismuth oxide (Pb1/3Bi2/3)O1.4

  Nobuhiro Kumada, Akira Miura, Takahiro Takei, Masatomo Yashima

  Journal of Asian Ceramic Societies 2 (2) 150 - 153 2187-0764 2014 [Refereed][Not invited]
   

  The crystal structures of a pentavalent bismuthate, SrBi2O6 with the PbSb2O6-type structure and a lead bismuth oxide, (Pb1/3Bi2/3)O1.4 with the fluorite-type structure were refined by using neutron diffraction data. The final R-factors were Rwp=4.49, Rp=3.46, RI=4.50 and RF=1.70% for SrBi2O6 and Rwp=5.04, Rp=3.93, RI=5.47 and RF=4.26% for (Pb1/3Bi2/3)O1.4. SrBi2O6 prepared from NaBiO3·1.4H2O is the first example of the bismuthate with the PbSb2O6-type structure. The fluorite-type lead bismuth oxide, (Pb1/3Bi2/3)O1.4 was obtained by heating the PbSb2O6-type lead bismuthate, PbBi2O5.9·H2O which was prepared also from NaBiO3·1.4H2O. © 2014 The Ceramic Society of Japan and the Korean Ceramic Society.
• Soft-chemical synthesis and catalytic activity of Ni-Al and Co-Al layered double hydroxides (LDHs) intercalated with anions with different charge density

  Takahiro Takei, Akira Miura, Nobuhiro Kumada

  Journal of Asian Ceramic Societies 2 (3) 289 - 296 2187-0764 2014 [Refereed][Not invited]
   

  Co-Al and Ni-Al layered double hydroxides (LDHs) intercalated with three types of anionic molecules, dodecylsulfate (C12H25SO4-, DS), di-2-ethylsulfosuccinate ([COOC2H3EtBu]2C2H3SO3-, D2ES), and polytungstate (H2W12O4210-, HWO) were prepared by means of ion-exchange and co-precipitation processes. With the use of DS and D2ES as intercalation agents, high crystallinity was maintained after intercalation into the LDHs. In the case of HWO, the intercalated LDHs could be obtained by ion-exchange as well as co-precipitation with a decline in the crystallinity however, unreacted LDH was detected in the ion-exchange samples, and some unwanted phases such as hydroxide and pyrochlore were generated by the co-precipitation process. The maximum specific surface area and pore volume of the Ni-Al sample with intercalated HWO, prepared by the ion-exchange process were 74m2/g and 0.174mL/g, respectively. The occupancies of DS, D2ES, and HWO within the interlayer space were approximately 0.3-0.4, 0.5-0.6, and 0.1-0.2, respectively, in the Co-Al and Ni-Al LDHs. Analysis of the catalytic activity demonstrated that the DS-intercalated Ni-Al LDH sample exhibited relatively good catalytic activity for conversion of cyclohexanol to cyclohexanone. © 2014 The Ceramic Society of Japan and the Korean Ceramic Society.
• Structural analysis and superconducting properties of F-substituted NdOBiS2single crystals

  Masanori Nagao, Satoshi Demura, Keita Deguchi, Akira Miura, Satoshi Watauchi, Takahiro Takei, Yoshihiko Takano, Nobuhiro Kumada, Isao Tanaka

  Journal of the Physical Society of Japan 82 (11) 113701 - 113701 0031-9015 2013/11 [Refereed][Not invited]
   

  F-substituted NdOBiS2superconducting single crystals were grown using CsCl/KCl.ux. This is the.rst example of the single-crystal growth of a BiS2-based superconductor. The obtained single crystals had a plate-like shape with a size of 1-2mm and a well-developed ab-plane. The crystal structure of the grown crystals was determined by singlecrystal X-ray di.raction analysis to be the tetragonal space group P4=nmm (29) with a = 3:996(3) and c = 13:464(6)Å. The chemical formula of the grown crystals was approximately Nd0.98±0.06O 0.7±0.1F0.3±0.1Bi 0.98±0.04S2, and Cs, K, and Cl were not detected in the grown crystals by electron probe microanalysis. The grown crystals had a critical temperature of approximately 5K. The superconducting anisotropy of the single crystals was estimated to be about 30 from the e.ective mass model and the upper critical.eld. © 2013 The Physical Society of Japan.
• Low-Temperature Nitridation of Manganese and Iron Oxides Using NaNH2 Molten Salt

  Akira Miura, Takahiro Takei, Nobuhiro Kumada

  INORGANIC CHEMISTRY 52 (20) 11787 - 11791 0020-1669 2013/10 [Refereed][Not invited]
   

  Manganese and iron nitrides are important functional materials, but their synthesis processes from oxides often require high temperatures. Herein, we show a novel meta-synthesis method for manganese and iron nitrides by low-temperature nitridation of their oxides using NaNH2 molten salt as the nitrogen source in an autoclave at 240 degrees C. With this method, nitridation of micrometer-sized oxide particles kept their initial morphologies, but the size of the primary particles decreased. The thermodynamic driving force is considered to be the conversion of oxides to sodium hydroxide, and the kinetic of nitridation is improved by the decrease of particle size and the low melting point of NaNH2. This technique as developed here has the advantages of low reaction temperature, reduced consumption of ammonia, employing nonspecialized equipment, and providing facile control of the reactions for producing nitrides from oxides.
• Hydrothermal Synthesis of BiFeO3 Fine Particles

  Kobayashi, Miyabi, Kumada, Nobuhiro, Miura, Akira, Takei, Takahiro, Fujii, Ichiro, Wada, Satoshi

  Transactions of the Materials Research Society of Japan The Materials Research Society of Japan 38 (1) 53 - 55 1382-3469 2013/10 [Refereed][Not invited]
   

  Fine particles of BiFeO₃ were prepared from bismuth nitrate and iron nitrate in KOH solution by hydrothermal reaction. A single phase of BiFeO₃ was prepared under hydrothermal condition of K/Bi ≥ 120 and above 180 °C. The TG curves of single phase of BiFeO₃ indicated that the products included a small amount of OH group or water in spite of no detection of potassium atom by EDX. The particle size of BiFeO₃ was ～ 10 μm and 10 ～ 20 μm for the products at 180 and 220 °C, respectively. The particle prepared at 220 °C was formed by aggregation of ～ 10 nm size particles with a cubic shape. From the pH dependence of ζ-potential the isoelectric point was about three.
• Bonding preference of carbon, nitrogen, and oxygen in niobium-based rock-salt structures

  Akira Miura, Takahiro Takei, Nobuhiro Kumada, Satoshi Wada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa

  Inorganic Chemistry 52 (17) 9699 - 9701 0020-1669 2013/09/02 [Refereed][Not invited]
   

  Carbon, nitrogen, and oxygen are essential components in solid-state materials. However, understanding their preference on the bonding to metals has not been straightforward. Here, niobium carbide, nitride, and oxide with simple rock-salt-based structures were analyzed by first-principles calculations and synchrotron X-ray diffraction. We found that an increase in the atomic number from carbon to oxygen formed fewer and shorter bonds to metals with better hybridization of atomic orbitals. This can provide a simple guiding principle for understanding the bonding and designing carbides, nitrides, oxides, and mixed-anion compounds. © 2013 American Chemical Society.
• Soft-chemical treatment of transition-metal-containing layered double hydroxides and their application in porous materials

  Takahiro Takei, Akira Miura, Nobuhiro Kumada, Kiyoshi Okada

  Journal of Porous Materials 20 (4) 777 - 783 1380-2224 2013/08 [Refereed][Not invited]
   

  Layered double hydroxides (LDH) containing Co or Ni as the divalent cation and Al or Fe as the trivalent cation were prepared by hydrothermal treatment. The LDH phase containing Al can be prepared at a pH of ca. 7, whereas the LDH phase containing Fe can be prepared at pH 10. The chemical composition of the LDH was estimated by the calculation of the weighted mean electronegativity of the cations present in the aqueous metal solution. The decarbonated LDHs are intercalated by sodium dodecyl sulfate and can be exfoliated in 1-butanol solution by ultrasonication. The resulting LDH aggregates with a card-house structure that can then be deposited from these exfoliated colloidal solutions by sodium carbonate. For Ni/Al and Ni/Fe LDHs, in particular, the specific surface area and pore volume drastically increased owing to the card-house texture formed by exfoliation and redeposition. © 2012 Springer Science+Business Media New York.
• Conversion of calcium sulfite waste to hydroxyapatite

  Takahiro Takei, Naoto Imazawa, Akira Miura, Nobuhiro Kumada, Kiyohiko Ogihara

  Powder Technology 237 400 - 405 0032-5910 2013/03 [Refereed][Not invited]
   

  Calcium sulfite waste was successfully transformed to hydroxyapatite (HAp) by oxidation using H2O2, followed by reaction with (NH4)2HPO4 under an NH4OH atmosphere. A single phase hydroxyapatite was obtained by stirring at 60, 80, or 100°C rather than by hydrothermal treatment at 150°C. Such formation implied that the homogeneity of the solution was very important. The primary HAp particles obtained had columnar shape, which formed spongy secondary particles with a diameter of around 1μm. Such porous particles resulted from the dissolution rate of calcium sulfite. The HAp obtained had a relatively Ca-rich composition of around Ca/P=1.71, and the specific surface area was around 69m2/g. In adsorption tests for Cs+ and Cd2+ cations in artificial seawater, the prepared HAp, like the general HAp powder, could remove Cd2+ cations from the seawater. © 2012 Elsevier B.V.
• Synthesis and crystal structure of Mg 0.5NbO 2: An ion-exchange reaction with Mg 2 between trigonal [NbO 2] - layers

  Akira Miura, Takahiro Takei, Nobuhiro Kumada

  Journal of Solid State Chemistry 197 471 - 474 0022-4596 2013/01 [Refereed][Not invited]
   

  A new layered niobate, Mg 0.5NbO 2, was synthesized from LiNbO 2 through a cation-exchange reaction with Mg 2 at 450-550 °C. This is the first example of a topotactic reaction with an aliovalent cation between trigonal [NbO 2] - layers. It is proposed to be isostructural with LiNbO 2 (space group P6 3/mmc) with lattice parameters of a=2.9052(6) Å, c=10.625(15) Å. The lattice parameters and formation energy of Mg 0.5NbO 2 crystallized in LiNbO 2 form and other layered CaNb 2O 4 one were calculated by density functional theory. © 2012 Elsevier Inc. All rights reserved.
• Low temperature synthesis of 12CaO center dot 7Al(2)O(3) from calcium sulfite waste

  Takahiro Takei, Maho Nakamura, Akira Miura, Nobuhiro Kumada, Kiyohiko Ogihara

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 121 (1409) 31 - 35 1882-0743 2013/01 [Refereed][Not invited]
   

  One of the calcium aluminate, 12CaO center dot 7Al(2)O(3), was synthesized from calcium sulfite hemihydrate waste which was produced as a by-product of calcium polysulfide. The calcium sulfite waste was at first pre-treated by sodium salts, Na2CO3 and Na2C2O4. Then, the waste was converted to the CaCO3 and CaC2O4, respectively. From these pre-treated sample, 12CaO center dot 7Al(2)O(3) phase was formed at 850 degrees C for the converted CaCO3 from Na2CO3 and at 650 degrees C for the converted CaC2O4 from Na2C2O4. These crystallization temperatures are much lower than from reagent CaCO3 and CaC2O4 at 1250 and 850 degrees C, respectively. The reason of such reduction of crystallized temperature may result from impurity Fe2O3 including in the by-product. Actually, addition of Fe2O3 into the reagent CaCO3 posed decrease of crystallization temperature of 12CaO center dot 7Al(2)O(3) from 1250 to 1050 degrees C. (C)2013 The Ceramic Society of Japan. All rights reserved.
• Low temperature synthesis of ATiO(3) (A: Mg, Ca, Sr, Ba) by using molten salt

  Nobuhiro Kumada, Akira Miura, Takahiro Takei, Indri Badria Adilina, Syogo Shimazu

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 121 (1409) 74 - 79 1882-0743 2013/01 [Refereed][Not invited]
   

  Alkaline earth metal titanates ATiO(3) (A: Mg, Ca, Sr, Ba) were prepared from two types of layered potassium titanates [K2Ti2O5 and K0.6Ti1.85O4 (hereafter, Lss)] by using alkaline earth metal molten salts [ACl(2) + A(NO3)(2) (1:1)]. For A = Ca a single phase of perovskite-type compound was prepared at 600 degrees C by using both starting compounds and the reaction temperature was lower than in 400 degrees C that of the solid state reaction with TiO2 (anatase) and CaCO3. A single phase of perovskite-type SrTiO3 was obtained at 600 and 700 degrees C for K2Ti2O5 and Lss, respectively and these temperatures were much lower than that (1200 degrees C) of the solid state reaction with TiO2 (anatase) and SrCO3. In the case of perovskite-type BaTiO3 a single phase of perovskite-type compound was prepared at 700 degrees C by using both starting compounds and also this temperature was much lower than that (above 1300 degrees C) of the solid state reaction with TiO2 (anatase) and BaCO3. Although neither K2Ti2O5 nor Lss could produce a single phase of ilmenite-type MgTiO3, it was prepared by the solid state reaction with TiO2 (anatase) and magnesium basic carbonate at 900 degrees C. A single phase of ilmenite-type CdTiO3 was prepared from K2Ti2O5 by using cadmium molten salts [CdCl2 + Cd(NO3)(2) (1:1)] at 500 degrees C. By taking account of the fact that ilmenite-type CdTiO3 transforms to perovskite-type structure, this preparative method using layered potassium titanates with molten salts preferred to crystallize perovskite-type titanates at lower temperature rather than ilmenite-type ones. (C)2013 The Ceramic Society of Japan. All rights reserved.
• Effect of dispersion of sepiolite in sepiolite-NBR composite on the tensile strength

  T. Takei, R. Oda, A. Miura, N. Kumada, N. Kinomura, R. Ohki, H. Koshiyama

  COMPOSITES PART B-ENGINEERING 44 (1) 260 - 265 1359-8368 2013/01 [Refereed][Not invited]
   

  The effect of dispersion of sepiolite in a sepiolite-NBR composite on the tensile strength of the composite was examined. Fibrous sepiolite was ultrasonically treated in distilled water with various types of dispersant. The ultrasonicated sepiolite was mixed with NBR latex to form a sepiolite-NBR complex. The tensile strength of the complex was examined to evaluate the degree of dispersion of sepiolite. The tensile strength results for the composites confirmed that a lower ultrasonication frequency produced a high strength in the composite. The tensile strength actually increased from 3 to 8 MPa as a result of ultrasonication at 28 kHz. To improve and stabilize the dispersion state, five kinds of dispersant were used. The addition of two dispersants in particular, ammonium polycarboxylate and amino alcohol polyphosphate, resulted in an increase of the strength from 8 to 15-16 MPa. When the composites were heated at 450 degrees C, the strengths of the composites produced with and without the dispersant were approximately 1.4-1.7 and 0.85 MPa, respectively. Thus, the dispersant still affected the strength of the heated samples. (C) 2012 Elsevier Ltd. All rights reserved.
• Preparation and dielectric property of (Li0.12Na 0.88)NbO3-based solid solutions

  Nobuhiro Kumada, Naoko Ito, Akira Miura, Takahiro Takei, Satoshi Wada, Takayuki Watanabe

  Journal of the Ceramic Society of Japan 121 (1415) 544 - 549 1348-6535 2013 [Refereed][Not invited]
   

  Three solid solutions [(1-x)LNN-xBaTiO3 (BT), xBaZrO3 (BZ) and xK0.5Ba0.5Ti0.5Nb0.5O 3(KBTN)] based on (Li0.12Na0.88)NbO 3(LNN) with the rhombohedral symmetry were prepared by conventional solid state reaction and their dielectric property was investigated. In the LNN-BT system in x ≤ 0.6 a secondary phase was observed as well as the perovskite-type phase and the psudo-cubic and tetragonal single phases were observed in 0.7 ≤ x ≤ 0.94 and 0.95≤ x ̄ 1.0, respectively. In LNN-BZ and LNN-KBTN systems single phases of the compounds with the rhombohedral symmetry were formed in x ≤ 0.05. The length of the a-axis increased with content of BZ or KBTN and that of the c-axis was almost unchanged except x = 0.1 for LNN-BZ. The secondary phase with the tetragonal tungsten bronze-type (TTB) structure was observed in wide composition range of these solid solutions, and LixBa2NaNb5-xMxO15(M: Ti, Zr) with the TTB-type structure was prepared and their crystal structure and dielectric property were investigated. ©2013 The Ceramic Society of Japan. All rights reserved.
• Synthesis of Wurtzite-Type InN Crystals by Low-Temperature Nitridation of LiInO2 Using NaNH2 Flux

  Akira Miura, Takahiro Takei, Nobuhiro Kumada

  CRYSTAL GROWTH & DESIGN 12 (9) 4545 - 4547 1528-7483 2012/09 [Refereed][Not invited]
   

  Nitridation of oxides above 500 degrees C is a conventional route for the synthesis of various oxynitrides and nitrides. However, this technique has the disadvantages of requiring a high temperature to break the strong metal and oxygen bonds and of low utilization efficiency of nitrogen sources such as toxic ammonia. Here, we show a simple low-temperature synthesis of InN nanocrystals via the nitridation of LiInO2 by NaNH2 flux at 240 degrees C in a Teflon-lined autoclave. The NaNH2 flux converted irregular-shaped LiInO2 powder to 50-300 nm InN nanocrystals with well-developed facets. The product crystallized in the hexagonal wurtzite structure with lattice parameters of a = 3.545 angstrom and c = 5.717 angstrom. Lithium in the starting oxide was found to be essential for this low-temperature nitridation.
• Acid-, base-, and heat-induced degradation behavior of Chinese sepiolite

  Akira Miura, Koji Nakazawa, Takahiro Takei, Nobuhiro Kumada, Nobukazu Kinomura, Ryosaku Ohki, Hiroki Koshiyama

  CERAMICS INTERNATIONAL 38 (6) 4677 - 4684 0272-8842 2012/08 [Refereed][Not invited]
   

  The stability of Chinese sepiolite with respect to acid, base, and heat treatments was examined based on changes that occur in its crystal structure, its morphology, its surface area, and the ions that leach into solution. Treatment in HCl for 3 h caused predominantly Mg2+ to leach and increased the surface area of the sepiolite. Increased temperature accelerated the leaching, resulting in the disappearance of the sepiolite phase above 100 degrees C. Treatment in NaOH caused Si4+ to be leached and this was accompanied by a minor change in the crystal structure of the sepiolite. Thermal treatment in air caused the manifestation of several types of dehydration behavior and the sepiolite was decomposed completely at above similar to 800 degrees C. Composite sheets of sepiolite and nitrile butadiene rubber were made from sepiolite after it had undergone various treatments. The tensile stress of each composite was measured and this is discussed with respect to its degradation features. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
• Preparation of porous material from waste bottle glass by hydrothermal treatment

  Takahiro Takei, Hiroaki Ota, Qiang Dong, Akira Miura, Yoshinori Yonesaki, Nobuhiro Kumada, Hiroyuki Takahashi

  CERAMICS INTERNATIONAL 38 (3) 2153 - 2157 0272-8842 2012/04 [Refereed][Not invited]
   

  Porous materials were prepared from colored waste glass by hydrothermal treatment with Na2CO3 aqueous solution. The resultant specific surface area was approximately 140 m(2)/g at maximum. Specific surface area increased at first, reached a maximum, and decreased gradually to be constant at approximately 60 m(2)/g depending on the period of hydrothermal treatment, irrespective of the concentration of Na2CO3 aqueous solution. However, the period at which the specific surface area reached maximum shortened with an increase in Na2CO3 concentration. On the other hand, the mass of the sample decreased and eventually saturated at approximately 30 mass% of the initial weight during the hydrothermal treatment. Both the dissolution of the mother glass and the formation of crystalline deposits, which were identified as calcite, zeolite-P and analcime, affected the porous structure of the treated samples. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
• Electrodeposition of exfoliated nanosheet colloid from the partially substituted birnessite and electrochemical property

  Takahiro Takei, Akira Miura, Nobuhiro Kumada

  COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 396 341 - 345 0927-7757 2012/02 [Refereed][Not invited]
   

  Partially substituted birnessite with Fe, Co, Ni and Cu for Mn was exfoliated to form nanosheet colloid and then their electrochemical properties were examined. The partially substituted birnessite can be exfoliated by tetrabutylammonium hydroxide acetonitrile solution. The electrodeposited films was grown from the exfoliated acetonitrile solution. The electrochemical capacitance of the films once increased at low substitution ratio and decreased with increase of the ratio. Within 10 atom% of the substitution ratio, the electrochemical capacitances are larger than that of non-substituted sample. Such increase seems to be related with DOS calculated by DV-X alpha. From calculated DOS curves, the band of 3d orbital of Mn4+ tends to broaden at low substitution ratio and be restored with further increase of the substituent. The broadening results from increase of another Mn4+ circumstance, Mn4+O6 octahedron surrounded by both Mn3+ and substituent cation. (C) 2012 Elsevier B.V. All rights reserved.
• Vitreous phase coating on glaserite-type alkaline earth silicate blue phosphor BaCa2MgSi2O8:Eu2+

  Yoshinori Yonesaki, Qiang Dong, Nur Suhaiza Binti Mohamad, Akira Miura, Takahiro Takei, Junji Yamanaka, Nobuhiro Kumada, Nobukazu Kinomura

  JOURNAL OF ALLOYS AND COMPOUNDS 509 (35) 8738 - 8741 0925-8388 2011/09 [Refereed][Not invited]
   

  A simple solid-state reaction was used to apply a vitreous-phase coating onto Eu2+-doped BaCa2MgSi2O8 blue-phosphor particles. The vitreous phase was generated by liquid phase sintering at 1200 degrees C. The coated phosphor exhibited resistant to an acid dispersant. When a small amount of Al and La was added in raw materials, they were incorporated in the vitreous coating phase. (C) 2011 Elsevier B.V. All rights reserved.
• Calculation of the electronic structure of delafossite AgTaN2 from first principles

  Akira Miura, Michael Wessel, Richard Dronskowski

  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 119 (1392) 663 - 666 1882-0743 2011/08 [Refereed][Not invited]
   

  The electronic structure (band structure, DOS and COHP) of the delafossite nitride AgTaN2 was investigated on the basis of density-functional theory using the generalized-gradient approximation (GGA). AgTaN2 is predicted to be a semiconductor with an indirect band gap. The characters of the top of the valence band and the bottom of the conduction band are attributed to Ag-N antibonding and Ta-N antibonding interactions, respectively. These results were compared to the bonding situation in isostructural AgGaO2. With increasing pressure, the electronic structure of AgTaN2 changes. At a pressure of ca. 42 GPa, the indirect band gap should transform into a direct one, and at even higher pressures (above 65 GPa) AgTaN2 should become metallic. (C) 2011 The Ceramic Society of Japan. All rights reserved.
• Silver delafossite nitride, AgTaN2?

  Akira Miura, Michael Lowe, Brian M. Leonard, Chinmayee V. Subban, Yuji Masubuchi, Shinichi Kikkawa, Richard Dronskowski, Richard G. Hennig, Hector D. Abruna, Francis J. DiSalvo

  JOURNAL OF SOLID STATE CHEMISTRY 184 (1) 7 - 11 0022-4596 2011/01 [Refereed][Not invited]
   

  A new silver nitride, AgTaN2, was synthesized from NaTaN2 by a cation-exchange reaction, using a AgNO3-NH4NO3 flux at 175 degrees C Its crystal structure type is delafossite (R (3) over barm) with hexagonal lattice parameters of a=3.141(3) angstrom, c=18.81(2) angstrom, in which silver is linearly coordinated to nitrogen. Energy dispersive X-ray analysis and combustion nitrogen/oxygen analysis gave a composition with atomic ratios of Ag:Ta:N:O as 1.0:1.2(1):2.1(1):0.77(4), which is somewhat Ta rich and indicates some oxide formation. The X-ray photoelectron spectroscopy analysis showed a Ta- and O-rich surface and transmission electron microscope observation exhibited aggregates of ca. 4-5 nm-sized particles on the surface, which are probably related to the composition deviation from a AgTaN2. The lattice parameters of stoichiometric AgTaN2 calculated by density functional theory agree with the experimental ones, but the possibility of some oxygen incorporation and/or silver deficiency is not precluded. (C) 2010 Elsevier Inc. All rights reserved.
• Synthesis of Pt-Mo-N Thin Film and Catalytic Activity for Fuel Cells

  Akira Miura, Michele E. Tague, John M. Gregoire, Xiao-Dong Wen, R. Bruce van Dover, Hector D. Abruna, Francis J. DiSalvo

  CHEMISTRY OF MATERIALS 22 (11) 3451 - 3456 0897-4756 2010/06 [Refereed][Not invited]
   

  Although platinum and platinum-based intermetallic alloys have been extensively studied as catalysts for proton exchange membrane fuel cells, platinum-based nitride catalysts have been relatively unexplored. We report the synthesis and characterization of a platinum-based nitride, Pt(2)Mo(3)N, using a composition spread thin-film deposition technique. The Pt(2)Mo(3)N thin film was generated by codeposition of platinum and molybdenum and subsequent heat treatment in an ammonia flow at 800 degrees C for 6 h. The thin film was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electrochemical tests, including the assessment of catalytic activity toward the oxidation of methanol and formic acid and the reduction of oxygen. The nitride film was smooth and contained single-phase, nearly stoichiometric Pt(2)Mo(3)N. Cyclic voltammograms of Pt(2)Mo(3)N in 0.1 M H(2)SO(4) demonstrated electrochemical stability far greater than that of a PtMo alloy with the same Pt:Mo ratio, indicating that the formation of the nitride phase enhances electrochemical stability. The ternary nitride exhibited oxidation currents in formic acid and methanol solutions above approximately 0.0 and 0.4 V vs an Ag/AgCl reference electrode, respectively. These are above the expected equilibrium oxidation potentials of approximately -0.2 V. The onset potential for oxygen reduction was estimated to be similar to 0.2 V vs Ag/AgCl, well below the equilibrium value of 1.0 V.
• Non-stoichiometric FexWN2: Leaching of Fe from layer-structured FeWN2

  Akira Miura, Xiao-Dong Wen, Hideki Abe, Grace Yau, Francis J. DiSalvo

  JOURNAL OF SOLID STATE CHEMISTRY 183 (2) 327 - 331 0022-4596 2010/02 [Refereed][Not invited]
   

  Non-stoichiometric FexWN2 (x similar to 0.72) was synthesized via leaching of Fe from layer-structured stoichiometric FeWN2 by soaking in Sulfuric acid at ca. 50 degrees C. The synthesized products were characterized by powder X-ray diffraction (pXRD), secondary electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and magnetic measurements. Non-stoichiometric FexWN2 has the same symmetry unit cell as stoichiometric FeWN2 (P6(3)/mmc), but the lattice parameters change: the a-axis expands by 0.16% while the c-axis decreases by 1.5%. Polycrystalline powder of FexWN2 showed similar morphologies as those of FeWN2. The calculated electronic structure of stoichiometric FeWN2 shows a more ionic-bonding character between Fe and N than that between W and N, which presumably allows for the partial Fe leaching from between the W-N prismatic layers. The magnetic susceptibility of FexWN2 smoothly decreases with increasing temperature from 3 to 300 K, unlike the broad maximum seen near 27 K in stoichiometric FeWN2. (C) 2009 Elsevier Inc. All rights reserved.
• Synthesis and characterization of Zn-doped GaN crystals by simultaneous carbothermal reduction and nitridation of Ga2O3 and ZnO

  Shiro Shimada, Hiroki Otani, Akira Miura, Takashi Sekiguchi, Masaaki Yokoyama

  JOURNAL OF CRYSTAL GROWTH 312 (3) 452 - 456 0022-0248 2010/01 [Refereed][Not invited]
   

  GaN powders doped with varying amounts of Zn were deposited on silica glass substrates at 1160 degrees C by reaction for 1 h of NH3 with gaseous Ga2O and Zn. These precursor gases were produced by reaction of C with Ga2O3 and ZnO, respectively, called carbothermal reduction and nitridation (CRN). For comparison, Zn-doped GaN powders were produced at 1160 degrees C by direct nitridation (DN) of ZnO/Ga2O3 and ZnGa2O4 powders with NH3. Zn-doped GaN single crystals of 1 x 0.5 mm(2) in size were grown in a silica glass crucible by the CRN method. The crystallinity of the GaN powders was determined by X-ray diffraction and their morphology was observed by scanning electron microscopy. The concentrations of 0 and Zn in the GaN powders were determined by the combustion and inductively coupled plasma methods. In-depth profiles of the O, H, and Zn concentrations in the GaN single crystals were determined by secondary ion mass spectroscopy. Cathodoluminescence (CL) observation of the GaN powders was performed to evaluate their quality. It is revealed that, compared with the powders prepared by DN, Zn-doped GaN powders produced by CRN exhibit very high CL intensities at 460 nm due to the presence of Zn. (C) 2009 Elsevier B.V. All rights reserved.
• Tuning of Metal-Metal Bonding by Counterion Size in Hypothetical AeTiO(2) Compounds

  Xiao-Dong Wen, Thomas J. Cahill, Roald Hoffmann, Akira Miura

  JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 131 (41) 14632 - + 0002-7863 2009/10 [Refereed][Not invited]
   

  In a theoretical study of a "defect perovskite" structure of stoichiometry AeTiO(2) (AE alkaline earth metal, Be, Mg, Ca, Sr, and Ba), we find substantial Ti-Ti bonding tuned by the size of the Ae(2+) cation. The bonding is one-dimensional, partially a, partially H. These formal d(2) systems are expected to be nonmagnetic and metallic. A competing (for same Ae) structural alternative, an ordered rock-salt structure, is magnetic.
• Synthesis of Intermetallic PtZn Nanoparticles by Reaction of Pt Nanoparticles with Zn Vapor and Their Application as Fuel Cell Catalysts

  Akira Miura, Hongsen Wang, Brian M. Leonard, Hector D. Abruna, Francis J. DiSalvo

  CHEMISTRY OF MATERIALS 21 (13) 2661 - 2667 0897-4756 2009/07 [Refereed][Not invited]
   

  Intermetallic PtZn nanoparticles with stable and high activities toward formic acid and methanol electrooxidation were synthesized by reaction of carbon-supported Pt nanoparticles with Zn vapor at 500 degrees C for 8 h under flowing nitrogen at atmospheric pressure. The resulting well-dispersed 3-15 nm diameter PtZn nanoparticles were tetragonal phase (P4/mmm: a = 0.2842(1) nm, c = 0.3488(3) nm) and their Pt:Zn ratio was approximately 1:1. Reactions using unsupported Pt nanoparticles (< 5 nm domain size) produced aggregated masses consisting of 5-60 nm nanoparticles. The catalytic activities of supported PtZn nanoparticles toward formic acid and methanol electrooxidation were studied by differential electrochemical mass spectrometry (DEMS). The intermetallic PtZn nanoparticles exhibited higher currents For both formic acid and methanol oxidation than supported Pt nanoparticles with similar particle sizes, but the activity was not as high as that of PtPb. Finally, we established that vapor phase reactions of nano-Pt and M at temperatures sufficient to produce a vapor pressure of 1 x 10(-4) atm for M are generally successful (M: Bi, Tl, and Pb).
• Phase change and electrical resistivity of Zn-Mn-Ni-O-based NTC thermistors produced using IZC powder recycled from used dry batteries

  J. Takahashi, A. Miura, H. Itoh, K. Sawayama, T. Akazawa, K. Nebuka, H. Miura, M. Kishi

  CERAMICS INTERNATIONAL 34 (4) 853 - 857 0272-8842 2008/05 [Refereed][Not invited]
   

  Zn-Mn-Ni-Oxide-based NTC thermistors with variable Ni/Mn ratios were fabricated from powder mixtures of recycled IZC, and commercial MnCO3 and NiCO3. Solid phases and electrical resistivity of each sintered sample were studied as a function of Ni/Mn ratio, sintering temperature and sintering time. At 1200 degrees C for 2 h, samples with the Ni/Mn ratios of 0.38 and higher were found to consist of cubic spinel as a major phase. After sintering at 1250 degrees C for 10 h, densification proceeded with a phase change from cubic spinel to tetragonal one. The electrical resistivity of the samples obtained at 1200 degrees C for 2 h progressively decreased with an increasing Ni/Mn ratio up to 0.38, at which the value became the lowest (4.2 x 10(3) Omega cm, at room temperature) of all the samples fabricated. (C) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
• Vapor-phase growth of high-quality GaN single crystals in crucible by carbothermal reduction and nitridation of Ga2O3

  Akira Miura, Shiro Shimada, Takashi Sekiguchi, Masaaki Yokoyama, Bunsyo Mizobuchi

  JOURNAL OF CRYSTAL GROWTH 310 (3) 530 - 535 0022-0248 2008/02 [Refereed][Not invited]
   

  Highly crystalline gallium nitride (GaN) single crystals with good luminescence property were grown at 1200 degrees C for 2 h by the reaction between Ga2O and NH3 gases flowing into an incised silica crucible. The Ga2O vapor was generated by carbothermal reduction of Ga2O3 at 970 degrees C. The effect of Ga2O generation rate (2-23 mu mol/min) on the morphology, crystallinity, cathodoluminescence property and impurity content was investigated. As the generation rate of Ga2O increased, the crystals changed from prismatic to needle-like shape, with a maximum prismatic crystal size of 1.7 mm x 0.3 min x 0.3 mm at the rate of 15 mu mol/min. The prismatic crystals were found to have high crystallinity by the narrow full-width at a half-maximum (40-70 arcsec) of their (10 (1) over bar0) X-ray rocking curves. Their good luminescence property was indicated by the intense cathodoluminescence peaks centered at similar to 3.47 eV. A relatively high concentration of oxygen (5 x 10(20) atoms/cm(3)) was contained in the crystals, as measured by secondary ion mass spectroscopy. (C) 2007 Elsevier B.V. All rights reserved.
• Properties and electronic structure of heavily oxygen-doped GaN crystals

  Akira Miura, Shiro Shimada, Masaaki Yokoyama, Hiroto Tachikawa, Toshio Kitamura

  CHEMICAL PHYSICS LETTERS 451 (4-6) 222 - 225 0009-2614 2008/01 [Refereed][Not invited]
   

  We investigated the properties of heavily oxygen-doped single GaN crystals and proposed their electronic structure based on first-principle calculations. The crystals were grown by carbothermal reduction and nitridation of Ga2O3 at 1180 degrees C for 2-8 h. The crystal were found to have high-crystallinity and high-concentration oxygen (4-9 x 10(20) atoms/cm(3)). Cathodoluminescence measurements of the 8-h-grown crystals showed a shift of band-edge-related luminescence peak toward higher energy (ca. 120 meV). Density of state of oxygen-doped GaN supercell was calculated using the first-principle to support this upward shift of luminescence energy. (C) 2007 Elsevier B.V. All rights reserved.
• Synthesis and characterization of Ge-doped gan crystalline powders deposited on graphite and silica glass substrates

  Shiro Shimada, Yoko Miura, Akira Miura, Takashi Sekiguchi

  Crystal Growth and Design 7 (7) 1251 - 1255 1528-7483 2007/07 [Refereed][Not invited]
   

  Gallium nitride (GaN) powders doped with various amounts of Ge were deposited at 1000 and 1180 °C on graphite and silica glass substrates by a 1-h reaction of NH3 with gaseous Ga2O and GeO, produced by the reaction of carbon with Ga2O3 and GeO2, respectively. The crystallinity of the GaN powders was determined by X-ray diffraction (XRD) and Raman spectroscopy, and their morphology was observed by scanning electron microscopy. The luminescence of the powders was measured at room temperature by cathodoluminescence (CL) to evaluate the quality of the GaN crystals. The influence of Ge-doping of the GaN powders on their crystallinity, morphology, and luminescence is discussed on the basis of the XRD, Raman spectroscopy, and CL results. It is shown that Ge-doped GaN crystals exhibit very high CL intensities accompanied by the elimination of defect-related emission at 430 nm. © 2007 American Chemical Society.
• Growth and characterization of millimeter-sized GaN crystals by carbothermal reduction and nitridation of Ga2O3

  Akira Miura, Shiro Shimada, Takashi Sekiguchi

  JOURNAL OF CRYSTAL GROWTH 299 (1) 22 - 27 0022-0248 2007/02 [Refereed][Not invited]
   

  Micrometer- to millimeter-sized wurtzite-type GaN crystals were grown on graphite substrates and at the edge of a silica glass tube at 840-1200 degrees C for 5-120 min by the reaction of NH3 With Ga2O vapor, produced by carbothermal reduction of Ga2O3 powder at 970 degrees C. The GaN crystals were characterized by scanning electron microscopy, optical microscopy, X-ray diffraction, Raman spectroscopy and cathodoluminescence. As the growth temperature and time were increased, the size of crystals grown on the graphite substrate drastically increased from several hundreds nanometer to a few hundred microns with the crystal habits changing from plate to bowtie or hexagonal prism. At the edge of a silica glass tube, the bar-shaped crystals of 1-3 mm, in length were obtained at the 1200 degrees C for 120 min. It was found that carbothermal reduction and high-temperature nitridation of Ga2O3 produced relatively large crystals (similar to 3 min) with better quality. (c) 2006 Elsevier B.V. All rights reserved.
• Vapor phase growth of GaN crystals with different morphologies and orientations on graphite and sapphire substrates

  Akira Miura, Shiro Shimada

  MATERIALS RESEARCH BULLETIN 41 (9) 1775 - 1782 0025-5408 2006/09 [Refereed][Not invited]
   

  GaN crystals were grown on graphite and sapphire substrates at 990-1050 degrees C by reaction of Ga2O with flowing NH3. Ga2O gas was produced at a constant rate (1.3 wt% min(-1)) by reaction of Ga2O3 with carbon at 1000-1060 degrees C. The effect of NH3 concentration (3-100 vol%) and the nature of the substrate on the morphology and orientation of the GaN crystals were determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and selected area electron diffraction. It was found that sheet and plate-like crystals grew at different orientations to the substrate with different NH3 concentrations and substrates. (c) 2006 Elsevier Ltd. All rights reserved.

MISC

• Synthesis and Superconducting Properties of (Pt_0.2Ir_0.8)₃Zr₅ with a Chiral Crystal Structure

  渡邊雄翔, 有馬寛人, 山下愛智, 三浦章, 森吉千佳子, 後藤陽介, LEE C. H., 東中隆二, 臼井秀知, 水口佳一  日本物理学会講演概要集(CD-ROM)  78-  (2)  2023
• In-situ Xray diffraction during high-temperature and high-pressure treatment of SnS₂

  相川皆子, 田所泰志郎, 横倉聖也, 横倉聖也, 牧紘太郎, 三浦章, 三浦章, 河口沙織, 門林宏和, 岡健太, 島田敏宏, 島田敏宏  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  84th-  2023
• Preparation and characterization of low-melting LiF-SnO-P₂O₅ glasses

  柴田姫芽, 藤井雄太, 三浦章, 鱒渕友治, 忠永清治  ガラスおよびフォトニクス材料討論会講演要旨集  64th-  2023
• Electrochemical CO₂ reduction by Zn-containing layered double hydroxides

  中里亮介, 松本慶江子, 山口登, ROSERO-NAVARRO Nataly Carolina, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(Web)  36th-  2023
• Liquid-phase Synthesis of Sulfide Electrolytes and Synthesis Mechanism

  MIURA Akira, CALPA Marcela, ROSERO-NAVARRO Nataly Carolina, TADANAGA Kiyoharu  Journal of the Japan Society of Powder and Powder Metallurgy  69-  (3)  95  -98  2022/03/15  

  Sulfide electrolytes are key materials for all-solid-state batteries. However, the synthesis of sulfide electrolytes needs care to avoid moisture and to prevent the loss of sulfur species. In this minireview, we introduce the chronological history, property, and synthesis of sulfide solid electrolytes, especially that using organic solvents. We show our recent achievements in the synthesis mechanism of β-Li₃PS₄ via solution process by analyzing intermediates.
• Electrocatalitic property of Transition Metal Containing Layered Double Hydroxides for CO₂ electrochemical reduction

  忠永清治, 山口登, 松本慶江子, ROSERO-NAVARRO Nataly Carolina, 中里亮介, 三浦章  日本セラミックス協会秋季シンポジウム講演予稿集(Web)  35th-  2022
• Direct Observation and Computational Modeling of Solid-State Ceramics Synthesis

  MIURA Akira  Nihon Kessho Gakkaishi  63-  (4)  255  -256  2021/12/15  [Not refereed]
  
• Nitridation of solution-process derived Sr-Ta oxide precursor thin film with solid nitrogen sources

  樋口亜門, ROSERO-NAVARRO Nataly Calorina, 三浦章, 鱒渕友治, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  33rd-  2020
• Selective metathesis synthesis of MgCr₂S₄

  三浦章, 井藤浩明, BARTEL Christopher J., SUN Wenhao, ROSERO-NAVARRO Nataly Carolina, 忠永清治, 中田博子, 前田和彦, CEDER Gerbrand, CEDER Gerbrand  日本セラミックス協会年会講演予稿集(CD-ROM)  2020-  2020
• Preparation of nano-structured ZrO₂-Al₂O₃ bilayer thin films by sol-gel process and its application to hydrophobic coating films

  清藤太郎, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治  日本セラミックス協会年会講演予稿集(CD-ROM)  2020-  2020
• Development of mechanoredox reactions using ball milling and piezoelectric materials

  久保田浩司, 久保田浩司, PANG Yadong, 三浦章, 伊藤肇, 伊藤肇  日本化学会春季年会講演予稿集(CD-ROM)  100th-  2020
• Investigation of relationship between mixing entropy of RE site and superconducting properties for REOBiS₂ superconducting single crystals

  藤田勇真, 長尾雅則, 丸山祐樹, 綿打敏司, 田中功, 三浦章, 平井慈人, 高野義彦  日本セラミックス協会関東支部研究発表会講演要旨集  36th-  2020
• Growth and superconducting properties of REOBiS₂(RE=La+Ce+Pr+Nd+Sm) single crystals

  藤田勇真, 長尾雅則, 三浦章, 平井慈人, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  81st-  2020
• Dependence of Ce valence state and lattice parameters on superconductivity in (Ce,Nd)OBiS₂ superconductors

  花田祐二, 長尾雅則, 三浦章, 平井慈人, 中野目滉介, 丸山祐樹, 綿打敏司, 武井貴弘, 熊田伸弘, 高野義彦, 田中功  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  81st-  2020
• Nb-Bi-Se系化合物の単結晶育成とその超伝導特性の評価

  長尾雅則, 田中将嗣, 堀部陽一, 三浦章, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  応用物理学会春季学術講演会講演予稿集(CD-ROM)  66th-  2019
• Nb-Bi-Se系化合物の単結晶育成とその超伝導特性

  長尾雅則, 田中将嗣, 堀部陽一, 三浦章, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  日本物理学会講演概要集(CD-ROM)  74-  (1)  2019
• ペロブスカイト型有機-無機ハロゲン化鉛を電極材料として用いた全固体リチウム二次電池の構築

  藤井雄太, RAMIREZ Daniel, ROSERO-NAVARRO Nataly Carolina, JULIAN Domingo, 三浦章, JARAMILLO Franklin, 忠永清治  電気化学会大会講演要旨集(CD-ROM)  86th-  2019
• リチウムイオン伝導性無機-有機ハイブリッドの合成および正極-ガーネット型酸化物固体電解質界面への応用

  梶浦龍之介, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治  電気化学会大会講演要旨集(CD-ROM)  86th-  2019
• シリカフィラーを添加したメチル-フェニルシルセスキオキサン透明厚膜の作製

  井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司  日本ゾル-ゲル学会討論会講演予稿集  17th-  2019
• Sm(O,F)BiS₂単結晶の育成と超伝導特性の評価

  木南幸希, 花田祐二, 長尾雅則, 三浦章, 後藤陽介, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  80th-  2019
• Sm(O,F)BiS₂超伝導体単結晶の育成

  木南幸希, 花田祐二, 長尾雅則, 三浦章, 後藤陽介, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  日本物理学会講演概要集(CD-ROM)  74-  (2)  2019
• 自己燃焼反応による新規マンガンモリブデン窒化物の合成

  三浦章, 小田原仁, ROSERO-NAVARRO Nataly Carolina, 忠永清治, 長尾雅則, 田中功  日本セラミックス協会年会講演予稿集(CD-ROM)  2019-  2019
• ゾル-ゲル法によるシリカを添加したメチル-フェニルシルセスキオキサン厚膜の作製

  井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司  日本セラミックス協会年会講演予稿集(CD-ROM)  2019-  2019
• Liquid-phase synthesis of Li₂S-P₂S₅ solid electrolyte by microwave heating

  三浦章, 馬庭陸, ROSERO-NAVARRO Nataly Carolina, 忠永清治  電池討論会PDF要旨集(CD-ROM)  60th-  2019
• Insertion/extration behavior of magnesium ions into olivine-type FePO₄

  山内紳伍, 松井雅樹, 三浦章, 後藤陽介, 牧秀志, 水畑穣  電池討論会PDF要旨集(CD-ROM)  60th-  2019
• Growth and characterization of BiS₂-based layered superconductor Sm(O,F)BiS₂ single crystals

  木南幸希, 花田祐二, 長尾雅則, 丸山祐樹, 綿打敏司, 田中功, 三浦章, 後藤陽介, 高野義彦  日本セラミックス協会関東支部研究発表会講演要旨集  35th-  2019
• マテリアルプロジェクトと自己燃焼反応を組み合わせた新規三元系窒化物の探索

  三浦章  日本材料科学会学術講演大会講演予稿集  2019-  2019
• 液相法による全固体リチウム二次電池用Li₆PS₅Cl固体電解質の作製における溶媒の影響

  丹羽葉月, NAVARRO Nataly Carolina Rosero, 三浦章, 忠永清治  電気化学会大会講演要旨集(CD-ROM)  85th-  2018
• Li₃SbS₄の合成・結晶構造およびLi⁺伝導性

  藤井雄太, 三浦章, ROSERO-NAVARRO N.C., 忠永清治, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘  日本セラミックス協会年会講演予稿集(CD-ROM)  2018-  2018
• ペロブスカイト型酸窒化物BaTaO₂Nの爆発的反応合成

  小田原仁, 三浦章, ROSERO-NAVARRO Nataly Carolina, 忠永清治  日本セラミックス協会年会講演予稿集(CD-ROM)  2018-  2018
• NaInS_2-xSe_x(x=0.5,1,1.5)の結晶構造および光吸収

  三浦章, 高橋夏海, 長尾雅則, 綿打敏司, 田中功, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘, ROSERO-NAVARRO N.C., 忠永清治  日本セラミックス協会年会講演予稿集(CD-ROM)  2018-  2018
• フェニルシルセスキオキサンゲルの熱軟化挙動を利用した厚膜作製

  忠永清治, 井上雄太, NAVARRO N.C. Rosero, 三浦章, 笠作衛, 幸塚広光, 米田裕和, 新開誠司  日本セラミックス協会年会講演予稿集(CD-ROM)  2018-  2018
• フェニルシルセスキオキサンゲルの熱軟化を利用した透明厚膜作製

  井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司  日本ゾル-ゲル学会討論会講演予稿集  16th-  2018
• リチウムイオン伝導性を有するポリエチレンオキシド系無機-有機ハイブリッドの合成

  梶浦龍之介, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治  日本ゾル-ゲル学会討論会講演予稿集  16th-  2018
• La_0.1Ce_0.9(O,F)BiS₂超伝導体における磁気転移とCe価数の関係

  花田祐二, 長尾雅則, 松本凌, 三浦章, 丸山祐樹, 綿打敏司, 田中博美, 高野義彦, 田中功  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  79th-  2018
• (Ce,Pr)OBiS₂単結晶の育成とその超伝導特性

  長尾雅則, 三浦章, 花田祐二, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  日本物理学会講演概要集(CD-ROM)  73-  (2)  2018
• Ce_1-xPr_xOBiS₂単結晶におけるPr置換量と超伝導転移温度の関係

  長尾雅則, 三浦章, 花田祐二, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  79th-  2018
• Mg-Al系層状複水酸化物を固体電解質に用いたアンモニア水燃料電池の構築

  石山翔, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治  電気化学秋季大会講演要旨集(CD-ROM)  2018-  2018
• Fe-P-S正極を用いた全固体リチウム二次電池の充放電特性

  小林美咲, 藤井雄太, ROSERO NAVARRO N. C., 三浦章, 忠永清治  電気化学秋季大会講演要旨集(CD-ROM)  2018-  2018
• (La,Ce)OBiS₂単結晶育成と超伝導特性

  花田祐二, 長尾雅則, 丸山祐樹, 綿打敏司, 田中功, 三浦章  日本セラミックス協会関東支部研究発表会講演要旨集  34th-  2018
• Morphology-Controlled Synthesis of Li₆PS₅Cl

  三浦章, ROSERO-NAVARRO Nataly Carolina, 忠永清治  電池討論会講演要旨集  59th-  2018
• Growth and characterization of single crystals of (Ce,R)OBiS₂ (R=La, Nd) superconductors

  花田祐二, 長尾雅則, 三浦章, 丸山祐樹, 綿打敏司, 高野義彦, 田中功  Journal of Flux Growth  13-  (2)  2018
• LiZnBO₃:Mnの合成と中性子イメージングへの応用

  川又俊介, 樋口幹雄, 金子純一, 竹谷篤, 小林知洋, 若林泰生, 大竹淑恵, 三浦章, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  31st-  2018
• 液相法で作製した酸化銅薄膜の尿素を用いた窒化

  大東侑生, 三浦章, ROSERO NAVARRO Nataly Carolina, 忠永清治  セラミックス基礎科学討論会講演要旨集  56th-  2018
• 浮遊帯溶融法によるYbドープK₂NiF₄型およびメリライト型酸化物単結晶の育成

  近添慎弥, 樋口幹雄, 樋口幹雄, 小川貴代, 和田智之, 緑川克美, 鱒渕友治, 三浦章, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  31st-  2018
• 層状酸硫化物LnOInS₂(Ln=La,Ce,Pr,Sm)の構造と物性

  井藤浩明, 三浦章, ROSERO-NAVARRO Nataly C., 水口佳一, 後藤陽介, 森吉千佳子, 黒岩芳弘, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  31st-  2018
• (Ce,Pr)OBiS₂の構造と超伝導

  三浦章, 長尾雅則, 綿打敏司, 田中功, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘, ROSERO-NAVARRO Nataly Carolina, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  31st-  2018
• 焼結助剤を用いたLi₇La₃Zr₂O₁₂系リチウムイオン伝導体の低温焼結とその評価

  竹當知矩, ROSERO NAVARRO Nataly Carolina, 三浦章, 忠永清治  セラミックス基礎科学討論会講演要旨集  56th-  2018
• 大面積(Gd,La)₂Si₂O₇:Ce多結晶薄板の作製とその対アルファ線シンチレーション特性

  福島光, 樋口幹雄, 金子純一, 三浦章, 忠永清治  セラミックス基礎科学討論会講演要旨集  56th-  2018
• SiO₂フィラーを添加したフェニルシルセスキオキサン透明厚膜の作製

  井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  31st-  2018
• アミド溶液を介した酸化インジウム薄膜への窒素ドープ

  成瀬雅浩, 三浦章, ROSERO-NAVARRO Nataly Carolina, 忠永清治, 伊左治忠之, 前田真一, 藤本修  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  31st-  2018
• Synchrotron powder X-ray diffraction and structural analysis of Eu0.5La0.5FBiS2-xSex

  Akira Miura  Journal of Physics: Conference Series  871-  2017/07/26  [Not refereed][Not invited]
   

  © Published under licence by IOP Publishing Ltd. Eu0.5La0.5FBiS2-xSex is a new BiS2-based superconductor system. In Eu0.5La0.5FBiS2-xSex, electron carriers are doped to the BiS2 layer by the substitution of Eu by La. Bulk superconductivity in this system is induced by increasing the in-plane chemical pressure, which is controlled by the Se concentration (x). In this study, we have analysed the crystal structure of Eu0.5La0.5FBiS2-xSex using synchrotron powder diffraction and the Rietveld refinement. The precise determination of the structural parameters and thermal factors suggest that the emergence of bulk superconductivity in Eu0.5La0.5FBiS2-xSex is achieved by the enhanced in-plane chemical pressure and the decrease in in-plane disorder.
• 酸窒化物による新しい酸素還元触媒の開発

  三浦章, 忠永清治  化学  71-  (11)  70‐71  2016/11/01  [Not refereed][Not invited]
  
• NaNH₂融液を用いたマンガン酸窒化物の合成とその酸素還元触媒能

  三浦章, ROSERO-NAVARRO Carolina, 鱒渕友治, 樋口幹雄, 吉川信一, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  29th-  2016
• 透光性LiYSiO₄:Ce多結晶薄板の作製とそのシンチレーション特性

  豊田紗希, 樋口幹雄, 金子純一, 三浦章, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  29th-  2016
• La置換Gd₂Si₂O₇:Ceの反応焼結とそのシンチレーション特性

  福島光, 樋口幹雄, 和氣嵩暁, 金子純一, 三浦章, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  29th-  2016
• 液相焼結による透光性Gd₂Si₂O₇:Ce薄板の作製とその対α線シンチレーション特性

  西方真美, 樋口幹雄, 坪田陽一, 金子純一, 山本誠一, 三浦章, 忠永清治  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  28th-  2015
• 30aCL-14 Metallic phase of partly-donor-substituted κ-(BEDT-TTF)_2Cu_2(CN)_3

  Yoneyama N., Kono R., Hamada K., Sasaki T., Nagao M., Tanaka I., Miura Akira, Takei T., Kumada N.  Meeting abstracts of the Physical Society of Japan  69-  (1)  866  -866  2014/03/05
• 28pBE-5 Growth and superconducting properties of RO(F)BiS2 single crystals

  Nagao Masanori, Demura Satoshi, Deguchi Keita, Miura Akira, Watauchi Satoshi, Takei Takahiro, Takano Yoshihiko, Kumada Nobuhiro, Tanaka Isao  Meeting abstracts of the Physical Society of Japan  69-  (1)  628  -628  2014/03/05
• RO(F)BiS₂(R:La,Ce,Nd)超伝導体単結晶のF濃度制御

  長尾雅則, 出村郷志, 出口啓太, 三浦章, 綿打敏司, 武井貴弘, 高野義彦, 熊田伸弘, 田中功  応用物理学会春季学術講演会講演予稿集(CD-ROM)  61st-  2014
• Preparation of Electrochemical Hybrid Film by Nanosheet from Layered Compounds

  TAKEI Takahiro, MIURA Akira, KUMADA Nobuhiro  Journal of the Society of Inorganic Materials, Japan : セッコウ・石灰・セメント・地球環境の科学  20-  (367)  396  -402  2013/11/01
• 無機化合物による希土類金属イオンの回収 (特集 先端的セラミックス材料の開発と応用)

  武井 貴弘, 三浦 章, 熊田 伸弘  ケミカルエンジニヤリング  58-  (6)  456  -461  2013/06
• Growth of BiS₂-based Superconducting Single Crystals Using CsCl-based Flux

  長尾雅則, 三浦章, 綿打敏司, 武井貴弘, 熊田伸弘, 田中功, 出村郷志, 出口啓太, 高野義彦  Journal of Flux Growth  8-  (2)  2013
• NdO(F)BiS₂超伝導体単結晶のフラックス育成

  長尾雅則, 出村郷志, 出口啓太, 三浦章, 綿打敏司, 武井貴弘, 高野義彦, 熊田伸弘, 田中功  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  74th-  2013
• Low temperature synthesis of 12CaO・7Al₂O₃ from calcium sulfite waste (Feature : Ceramics Processing through Energy Consumption Reduction (Green Processing))

  TAKEI Takahiro, NAKAMURA Maho, MIURA Akira  Journal of the Ceramic Society of Japan = 日本セラミックス協会学術論文誌  121-  (1409)  31  -35  2013/01
• 学大将を育てるクリスタル材料科学

  田中功, 長尾雅則, 山中淳二, 綿打敏司, 米﨑功記, 三浦章, 熊田伸弘  セラミックス  48-  865  -869  2013  [Not refereed][Not invited]
  
• セピオライトの特性とその応用

  三浦 章, 武井 貴弘, 熊田 伸弘  耐火物  65-  (1)  2  -7  2013  [Not refereed][Not invited]
  
• 炭素熱還元窒化法によるバルクGaN結晶の成長とイオンドーピング

  嶋田志郎, 三浦章  窒化物基板および格子整合基板の成長とデバイス特性(一章６部)  2009/10  [Not refereed][Not invited]
  
• Growth of GaN single crystals containing high-concentration oxygen and their property

  Miura Akira, Shimada Shiro, Sekiguchi Takashi, Yokoyama Masaaki, Mizobuchi Bunsyo, Kitamura Toshio  Preprints of Annual Meeting of The Ceramic Society of Japan
  Preprints of Fall Meeting of The Ceramic Society of Japan  2007F-  791  -791  2007  

  GaNへの不純物ドーピングは、その電気・光学特性に大きな影響を及ぼす。しかし、高濃度のドーピングが結晶の特性に与える影響は余り解っていない。そこで我々は、Ga₂O₃の炭素還元によって発生したGa₂Oガスを約1200℃、NH₃雰囲気で窒化することで、0.5 –1 at.%の高濃度の酸素を含む1-3 mmのGaN単結晶を育成し、その特性を評価した。育成した結晶は高結晶性と高電子密度 (>10¹⁹ cm-3)を有し、そのバンドギャップ付近の発光は約120 meVのブルーシフトを起こすことがわかった。このシフトを、酸素置換したGaN超格子の電子状態密度計算結果に基づいて説明した。

Books etc

• 固体材料開発のフロンティア : 熱力学的支配を超えた物質合成と新機能開拓を目指して

  三浦 章, 忠永清治 (Contributor14章 電池材料の非平衡合成と準安定性)
  化学同人 2024/03 (ISBN: 9784759814095) v, 167p, 図版 [4] p 

  本章では，準安定性の種類と定義を第一節で説明したのち，全固体電池に用いられる硫化物系固体電解質開発の歴史と残留準安定相と中間準安定相の関連性を第二節で説明する．筆者らが研究している固相合成反応の観察・論理化に関する進展を第三節に紹介する．
• ポストリチウムイオン二次電池開発 : 部材開発から解析・性能診断技術まで

  三浦, 章, 忠永, 清治 (Contributor第3編 第1章 第3節 ハロゲン化物系固体電解質)
  エヌ・ティー・エス 2023/07 (ISBN: 9784860438364) 38, 3, 10, 427, 8p
• 固相合成のその場XRD測定と新規材料探索

  三浦, 章 
  2022/10
• 第一原理計算を用いた合成反応解析 : 合成反応設計への挑戦1

  三浦 章 (Single workセラミックス. 57 (7). 2022, 439-441)
  2022/07
• 計算機化学とインフォマティクスによる材料の熱力学的安定性と反応性

  村岡 恒輝, 三浦 章 (Contributor第9章 第1節)
  技術情報協会 2020/08

Presentations

• How to Make Metastability? How to Use Metastability?  [Invited]

  Akira Miura

  Gordon Research Conference (Solid State Chemistry)  2024/07
• Li3YCl6の相転移  [Not invited]

  三浦 章, 井藤浩明, 忠永清治

  第49回固体イオニクス討論会  2023/11
• Na3YCl6 の無拡散相転移と機械的特性

  牧 紘太郎, 村岡 恒輝, 河口 沙織, 引間 和浩, 武藤 浩行, 松田 厚範, 山根 伊知郎, 島田 敏宏, 井藤 浩明, 水口 佳一, 森吉 千佳子, 池 広志, 中山 哲, ROSERO-NAVARRO Nataly Carolina, 三浦 章, 藤井 雄太, 忠永 清治

  日本セラミックス協会第36回秋季シンポジウム  2023/09
• KF粉砕によるKSbF4 固相合成経路の変換

  久末 竜駆, 三浦 章, 山下 愛智, 水口 佳一, 森吉 千佳子, 忠永 清治

  日本セラミックス協会第36回秋季シンポジウム  2023/09
• 大気下で合成したモリブデン窒化物  [Not invited]

  出村 萌々香, 三浦 章, 長尾 雅則, 李 哲虎, 後藤 陽介, 南部 雄亮, AVDEEV Maxim, 鱒渕 友治, 満留 敬人, 藤井 雄太, 忠永 清治

  日本セラミックス協会第36回秋季シンポジウム  2023/09
• 原料粉砕によるKSbF4固相合成経路の効果  [Not invited]

  久末竜駆, 三浦章, 山下愛智, 水口佳一, 森吉千佳子, 忠永清治

  日本化学会北海道支部夏季研究発表会  2023/09
• In-situ SEM-EDX システムとセラミックス合成のその場観察  [Not invited]

  三浦 章, 忠永 清治, Ansbro Avery-Ryan, Heron John・Sun Wenhao, 佐々木 俊輔, 宮武 耕志, 望月 貞彦

  日本セラミックス協会2023年年会  2023/03
• Synthesis-Structure Relationship Guided by Intermediate and Remnant Metastability  [Not invited]

  Akira Miura, Hiroaki Ito, Yuki Nakahira, Yosuke Goto, Yoshikazu Mizuguchi, Chikako Moriyoshi, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  2022 MRS Fall Meeting  2022/11
• 異方性応力印加によるNa3YCl6の格子膨張を伴う応力誘起相転移

  牧紘太郎, 村岡 恒輝, 河口沙織, 山根伊知郞, 島田敏宏, 井藤浩明, 中平夕貴, 森吉千佳子, 水口佳一, Nataly Carolina, Rosero-Navarro, 三浦章, 忠永清治

  令和4年度 日本セラミックス協会東北北海道支部研究発表会  2022/11
• Li3MCl6 中におけるMの秩序化 (M=Y, Dy-Tm)  [Not invited]

  井藤 浩明, 石松 直樹, 中平 夕貴, 後藤 陽介, 水口 佳一, 森吉 千佳子, Rosero-Navarro Nataly Carolina, 三浦 章, 忠永 清治

  日本セラミックス協会第35回秋季シンポジウム  2022/09
• Li2MP2S6(M=Mn,Fe,Co,Ni)の合成反応設計  [Not invited]

  野又 優, 三浦 章, Nataly Carolina Rosero-Navarro, 忠永 清治

  日本セラミックス協会第35回秋季シンポジウム  2022/09
• 固相合成反応のその場測定による準安定相の創出  [Invited]

  三浦 章

  日本物理学会2022年秋季大会・シンポジウムS3 物質中に現れる準安定性の科学：その理解と設計に基づく物性開拓  2022/09
• Large Rere-Earth Ions Kinetically Stabilize Metastable Li3LnCl6 (Ln: lanthanoids) Polymorphs  [Not invited]

  Hiroaki ITO, Yuki NAKAHIRA, Chikako MORIYOSHI, Naoki ISHIMATSU, Yosuke GOTO, Yoshikazu MIZUGUCHI, Nataly carolina, ROSERO NAVARRO, Akira MIURA, Kiyoharu TADANAGA

  The 5th International Union of Materials Research Societies-International Conference of Young Researchers on Advanced Materials  2022/08
• Synthesis of New Ternary Manganese Rare-Earth Nitrides by Self-Combustion Reactions and Evaluation of their Oxygen Reduction Reaction Activities  [Not invited]

  Hayato SAKAI, Akira MIURA, Shigeto HIRAI, Masanori NAGAO, Nataly carolina, ROSERO NAVARRO, Kiyoharu TADANAGA

  The 5th International Union of Materials Research Societies-International Conference of Young Researchers on Advanced Materials  2022/08
• 圧力印加によるNa3YCl6の相転移  [Not invited]

  牧紘太郎, 井藤浩明, 三浦 章, 忠永清治

  日本化学会北海道支部2022年夏季研究発表会  2022/07
• 放射光その場XRD・TEM・DFTを駆使したセラミックス固相合成反応機構の研究  [Invited]

  三浦章

  第35回日本放射光学会年会  2022/01
• Morphology-Controlled Synthesis of Li6PS5Cl  [Not invited]

  三浦章, ROSERO‐NAVARRO Nataly Carolina, 忠永清治

  電池討論会講演要旨集  2018/11
• Synthesis of Nitrides and Oxynitrides using NaNH2 for Emerging New Functional Materials  [Not invited]

  Miura, Akira, Kiyoharu, Tadanaga

  ICYRAM2018  2018/11  Adelaide
• (La,Ce)OBiS₂単結晶育成と超伝導特性  [Not invited]

  花田祐二, 長尾雅則, 丸山祐樹, 綿打敏司, 田中功, 三浦章

  日本セラミックス協会関東支部研究発表会講演要旨集  2018/09
• (Ce,Pr)OBiS₂単結晶の育成とその超伝導特性  [Not invited]

  長尾雅則, 三浦章, 花田祐二, 丸山祐樹, 綿打敏司, 高野義彦, 田中功

  日本物理学会講演概要集(CD-ROM)  2018/09
• Fe‐P‐S正極を用いた全固体リチウム二次電池の充放電特性  [Not invited]

  小林美咲, 藤井雄太, ROSERO NAVARRO N. C, 三浦章, 忠永清治

  電気化学秋季大会講演要旨集(CD‐ROM)  2018/09
• Mg‐Al系層状複水酸化物を固体電解質に用いたアンモニア水燃料電池の構築  [Not invited]

  石山翔, ROSERO‐NAVARRO Nataly Carolina, 三浦章, 忠永清治

  電気化学秋季大会講演要旨集(CD‐ROM)  2018/09
• La_0.1Ce_0.9(O,F)BiS₂超伝導体における磁気転移とCe価数の関係  [Not invited]

  花田祐二, 長尾雅則, 松本凌, 三浦章, 丸山祐樹, 綿打敏司, 田中博美, 高野義彦, 田中功

  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  2018/09
• Ce_1-xPr_xOBiS₂単結晶におけるPr置換量と超伝導転移温度の関係  [Not invited]

  長尾雅則, 三浦章, 花田祐二, 丸山祐樹, 綿打敏司, 高野義彦, 田中功

  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  2018/09
• Low-Temperature Synthesis of Nitrides/Oxynitrides and Emerging New Functional Materials by Controlling Electronic Structure  [Invited]

  Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  4th Workshop for Materials-Informatics Classic, MSSJ  2018/09
• アミド溶液を介した酸化インジウム薄膜への窒素ドープ  [Not invited]

  成瀬雅浩, 三浦章, ROSERO‐NAVARRO Nataly Carolina, 忠永清治, 伊左治忠之, 前田真一, 藤本修

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2018/08
• SiO₂フィラーを添加したフェニルシルセスキオキサン透明厚膜の作製  [Not invited]

  井上雄太, ROSERO‐NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2018/08
• (Ce,Pr)OBiS₂の構造と超伝導  [Not invited]

  三浦章, 長尾雅則, 綿打敏司, 田中功, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘, ROSERO‐NAVARRO Nataly Carolina, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2018/08
• 層状酸硫化物LnOInS₂(Ln=La,Ce,Pr,Sm)の構造と物性  [Not invited]

  井藤浩明, 三浦章, ROSERO‐NAVARRO Nataly C, 水口佳一, 後藤陽介, 森吉千佳子, 黒岩芳弘, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2018/08
• 浮遊帯溶融法によるYbドープK₂NiF₄型およびメリライト型酸化物単結晶の育成  [Not invited]

  近添慎弥, 樋口幹雄, 樋口幹雄, 小川貴代, 和田智之, 緑川克美, 鱒渕友治, 三浦章, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2018/08
• LiZnBO₃:Mnの合成と中性子イメージングへの応用  [Not invited]

  川又俊介, 樋口幹雄, 金子純一, 竹谷篤, 小林知洋, 若林泰生, 大竹淑恵, 三浦章, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2018/08
• Liquid-phase Chemistry of Sulfide Electrolyte For All-Solid-State Battery  [Invited]

  Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  the 8th International Symposium on Functional Materials  2018/08
• Explosive Synthesis of BaNbO2N  [Invited]

  Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  The 7th Advanced Functional Materials and Devices (AFMD 2017)  2018/08
• 二元系融点からの統計的な三元系融点予測  [Invited]

  三浦 章

  日本セラミックス協会基礎科学部会セミナー  2018/06
• ペロブスカイト型酸窒化物の爆発的反応合成  [Invited]

  三浦 章

  第5回MFD研究会  2018/03
• ペロブスカイト型酸窒化物BaTaO₂Nの爆発的反応合成  [Not invited]

  小田原仁, 三浦章, ROSERO‐NAVARRO Nataly Carolina, 忠永清治

  日本セラミックス協会年会講演予稿集(CD-ROM)  2018/03
• フェニルシルセスキオキサンゲルの熱軟化挙動を利用した厚膜作製  [Not invited]

  忠永清治, 井上雄太, NAVARRO N.C. Rosero, 三浦章, 笠作衛, 幸塚広光, 米田裕和, 新開誠司

  日本セラミックス協会年会講演予稿集(CD-ROM)  2018/03
• NaInS_2-xSe_x(x=0.5,1,1.5)の結晶構造および光吸収  [Not invited]

  三浦章, 高橋夏海, 長尾雅則, 綿打敏司, 田中功, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘, ROSERO‐NAVARRO N.C, 忠永清治

  日本セラミックス協会年会講演予稿集(CD-ROM)  2018/03
• 液相法による全固体リチウム二次電池用Li₆PS₅Cl固体電解質の作製における溶媒の影響  [Not invited]

  丹羽葉月, NAVARRO Nataly, Carolina Rosero, 三浦章, 忠永清治

  電気化学会大会講演要旨集(CD-ROM)  2018/02
• ペロブスカイト型酸窒化物BaNbO₂Nの爆発反応合成  [Not invited]

  小田原仁, 三浦章, ROSERO‐NAVVARO Nataly Carolina, 忠永清治

  化学系学協会北海道支部冬季研究発表会(Web)  2018/01
• リチウムイオン伝導性を有するポリエチレンオキシド系無機‐有機ハイブリッドの合成  [Not invited]

  梶浦龍之介, ROSERO‐NAVARRO Nataly Carolina, 三浦章, 忠永清治

  日本ゾル-ゲル学会討論会講演予稿集  2018
• Liquid-Phase Synthesis of Energy Materials with Multiple Anions: Mn(O,N) Electrocatalyst and Li6PS5Br Electrolyte  [Invited]

  Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga

  The 7th Advanced Functional Materials and Devices (AFMD 2017)  2017/12
• 二元系融点を用いた三元系融点の予測  [Not invited]

  三浦 章

  環境・生体データと統計解析（統計数理研究所共同研究集会）  2017/10
• R(O,F)PnS₂における結晶構造と超伝導性の関係  [Not invited]

  長尾雅則, 田中将嗣, 三浦章, 則竹史哉, 綿打敏司, 高野義彦, 田中功

  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  2017/09
• Design of Manganese Oxynitride Catalysts for the Oxygen Reduction Reaction  [Not invited]

  Akira Miura, Kiyoharu Tadanaga

  NTTH Joint Symposium  2017/07
• Low-temperature nitridation of oxides via NaNH2 melt  [Invited]

  Miura, Akira, Higuchi, Mikio, Tadanaga, Kiyoharu

  12th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM 12)  2017/05
• Crystal and electronic structures of LaOBiS2 and LaOInS22017  [Invited]

  Miura, Akira, Mizuguchi, Yoshikazu, Moriyoshi, Chikako, Kuroiwa, Yoshihiro, Higuchi, Mikio, Tadanaga, Kiyoharu

  12th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM 12)  2017/05
• 硫化物系固体電解質を用いた全固体リチウム二次電池におけるFePS₃電極の反応機構  [Not invited]

  藤井雄太, 三浦章, ROSERO Carolina, 水口佳一, 森吉千佳子, 黒岩芳弘, 樋口幹雄, 忠永清治

  電気化学会大会講演要旨集(CD-ROM)  2017/03
• Li₆PS₅Br前駆体溶液を用いた全固体リチウム二次電池用グラファイト電極複合体の作製  [Not invited]

  千田隼二郎, 三浦章, ROSERO Carolina, 樋口幹雄, 忠永清治

  電気化学会大会講演要旨集(CD-ROM)  2017/03
• 硫化物系固体電解質を用いた全固体リチウム二次電池におけるFePS₃電極の反応機構  [Not invited]

  藤井雄太, 三浦章, ROSERO Carolina, 水口佳一, 森吉千佳子, 黒岩芳弘, 樋口幹雄, 忠永清治

  電気化学会大会講演要旨集(CD-ROM)  2017/03
• Li₆PS₅Br前駆体溶液を用いた全固体リチウム二次電池用グラファイト電極複合体の作製  [Not invited]

  千田隼二郎, 三浦章, ROSERO Carolina, 樋口幹雄, 忠永清治

  電気化学会大会講演要旨集(CD-ROM)  2017/03
• NiPS₃正極活物質の硫化物系全固体リチウム二次電池における充放電機構  [Not invited]

  首藤祐作, 藤井雄太, 三浦章, カロリーナロゼロ, 樋口幹雄, 忠永清治, 水口佳一, 森吉千佳子, 黒岩芳弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2017/03
• 窒化物および酸窒化物の合成手法の開発と学理の構築  [Invited]

  三浦章

  日本セラミックス協会年会  2017/03
• 窒化物および酸窒化物の合成手法の開発と学理の構築  [Not invited]

  三浦章

  日本セラミックス協会年会講演予稿集(CD-ROM)  2017/03
• NiPS₃正極活物質の硫化物系全固体リチウム二次電池における充放電機構  [Not invited]

  首藤祐作, 藤井雄太, 三浦章, カロリーナロゼロ, 樋口幹雄, 忠永清治, 水口佳一, 森吉千佳子, 黒岩芳弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2017/03
• 硫化物系固体電解質を用いた全固体リチウム二次電池におけるFePS₃電極の充放電特性  [Not invited]

  藤井雄太, 三浦章, 樋口幹雄, 忠永清治

  電池討論会講演  2016/11  千葉
• マンガン酸窒化物の電子構造と酸素還元触媒能  [Invited]

  Miura, Akira

  電気化学会北海道支部・東海支部合同シンポジウム  2016/11
• 混合価数状態によるF‐free CeOBiS₂の超伝導  [Not invited]

  長尾雅則, 三浦章, 植田郁生, 綿打敏司, 田中功

  日本物理学会講演概要集  2016/09
• BiCh₂系層状化合物LaOBiS_2-xSe_xの熱電物性と結晶構造  [Not invited]

  水口佳一, 西田篤弘, 三浦大介, 三浦章, 西当弘隆, LEE C. H

  日本物理学会講演概要集(CD-ROM)  2016/09
• La置換Gd₂Si₂O₇:Ceの反応焼結とそのシンチレーション特性  [Not invited]

  福島光, 樋口幹雄, 和氣嵩暁, 金子純一, 三浦章, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• 超音波処理を用いたLi₆PS₅Brの液相合成と全固体電池用電極複合材料への応用  [Not invited]

  千田隼二郎, 三浦章, 樋口幹雄, 忠永清治, PHUC Nguyen H.H, 武藤浩行, 松田厚範

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• NiPS₃電極微粒子の合成と全固体リチウム二次電池における充放電特性  [Not invited]

  首藤祐作, 藤井雄太, 三浦章, 樋口幹雄, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• 透光性LiYSiO₄:Ce多結晶薄板の作製とそのシンチレーション特性  [Not invited]

  豊田紗希, 樋口幹雄, 金子純一, 三浦章, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• Li₆PS₅Cl前駆体溶液を用いた全固体リチウム二次電池正極複合材料の作製におけるバインダーの添加効果  [Not invited]

  木下泰希, ROSERO NAVARRO Nataly Carolina, 千田隼二郎, 三浦章, 樋口幹雄, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• 三元系相図へのインフォマティクスアプローチ  [Not invited]

  三浦章, 甫喜本司, 柳瀬隆, 長尾雅則, 島田敏宏, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• 熱CVD法によるTiCN硬質膜機械特性の向上と切削工具への適用  [Not invited]

  PASETH Anogsack, PASETH Anogsack, 福井治世, 山縣一夫, 三浦章, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• NaNH₂融液を用いたマンガン酸窒化物の合成とその酸素還元触媒能  [Not invited]

  三浦章, ROSERO‐NAVARRO Carolina, 鱒渕友治, 樋口幹雄, 吉川信一, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2016/08
• Synthesis of nitride nanoparticles using NaNH2 melt  [Invited]

  A. Miura, M. Higuchi, K. Tadanaga

  9th International Conference on High Temperature Ceramic Matrix Composites and Global Forum on Advanced Materials and Technologies for Sustainable Development 2016  2016/06
• マンガン酸窒化物における反結合軌道と酸素還元触媒能  [Invited]

  三浦章, 忠永清治

  化合物新磁性材料専門研究会  2016/06  東京
• FePS₃電極と硫化物系固体電解質を用いた全固体リチウム二次電池の構築  [Not invited]

  藤井雄太, 三浦章, 樋口幹雄, 忠永清治

  電気化学会大会講演要旨集(CD-ROM)  2016/03
• Pr(O,F)BiS₂単結晶におけるPr価数のXPSによる評価  [Not invited]

  石井聡, 本宮靖章, 三浦章, 長尾雅則

  応用物理学会春季学術講演会講演予稿集(CD-ROM)  2016/03
• 多環式芳香族環架橋ジホスホン酸と銅(II)塩を用いた水熱合成法による無機‐有機ハイブリッドの合成  [Not invited]

  飛世博愛, 標光一朗, 杉浦遼, ZAPICO Julian, 井戸田直和, 三浦章, 熊田伸弘, 菅原義之, 菅原義之

  日本セラミックス協会年会講演予稿集(CD-ROM)  2016/03
• 再構築法を用いたMg‐Al系LDH固体電解質膜の作製  [Not invited]

  五十嵐滉平, 三浦章, 樋口幹雄, 忠永清治

  日本セラミックス協会年会講演予稿集(CD-ROM)  2016/03
• Structure of BiS2 Layer in Bi4O4S3  [Not invited]

  Miura, Akira, Mizuguchi, Yoshikazu, Sugawara, Tsuyoshi, Takei, Takahiro, Kumada, Nobuhiro, Magome, Eisuke, Moriyoshi, Chikako, Kuroiwa, Yoshihiro, Miura, Osuke, Tadanaga, Kiyoharu

  The 2015 International Chemical Congress of Pacific Basin Societies  2015/12
• Structure of BiS2 Layer in Bi4O4S3  [Not invited]

  Akira Miura, Yoshikazu Mizuguchi, Tsuyoshi Sugawara, Takahiro Takei, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Kiyoharu Tadanaga

  Pacifichem 2015  2015/12  Honolulu
• NiPS₃電極と硫化物系固体電解質を用いた全固体リチウム二次電池の構築  [Not invited]

  藤井雄太, 三浦章, 樋口幹雄, 忠永清治

  電池討論会講演要旨集  2015/11
• 層状リン酸ジルコニウムへの希土類金属イオンの吸着特性  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  無機リン化学討論会講演要旨集  2015/09
• NaNH₂融液と酸化物からの新規窒化物合成手法の開発  [Invited]

  三浦章, 武井貴弘, 熊田伸弘, 樋口幹雄, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2015/09
• 液相焼結による透光性Gd₂Si₂O₇:Ce薄板の作製とその対α線シンチレーション特性  [Not invited]

  西方真美, 樋口幹雄, 坪田陽一, 金子純一, 山本誠一, 三浦章, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2015/09
• 遷移金属を含む層状複水酸化物の合成と金属‐空気二次電池への応用  [Not invited]

  久保田高志, 三浦章, 樋口幹雄, 忠永清治

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2015/09
• 層状ニオブ酸ペロブスカイトへのイオン交換と光触媒活性  [Not invited]

  武井貴弘, XU N, 三浦章, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2015/09
• RO(F)BiS₂(R:La,Ce,Pr,Nd)単結晶の組成制御とその評価  [Not invited]

  長尾雅則, 三浦章, 綿打敏司, 武井貴弘, 高野義彦, 熊田伸弘, 田中功

  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  2015/08
• Electronic structure, charge density and chemical bonding of Ta5N6  [Not invited]

  Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Takei Takahiro, Nobuhiro Kumada

  The 11th Pacific Rim Conference of Ceramic Societies  2015/08
• エチルセルロースをバインダーに用いた硫化物固体電解質の液相合成  [Not invited]

  木下泰希, 樋口幹雄, 忠永清治, 三浦章

  電気化学会大会講演要旨集(CD-ROM)  2015/03
• Ni‐Mn‐Fe系層状複水酸化物をアイオノマーとして用いた金属‐空気二次電池空気極の特性評価  [Not invited]

  久保田高志, 三浦章, 樋口幹雄, 忠永清治

  電気化学会大会講演要旨集(CD-ROM)  2015/03
• Ni系層状複水酸化物配向膜の作製と機能性酸化物への変換  [Not invited]

  武井貴弘, 布施宏樹, 三浦章, 熊田伸弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2015/03
• Bi₄O₄S₃の結晶構造と超伝導特性  [Not invited]

  三浦章, 水口佳一, 菅原剛, 樋口幹雄, 武井貴弘, 熊田伸弘, 馬込栄輔, 森吉千佳子, 黒岩芳弘, 三浦大介, 忠永清治

  日本セラミックス協会年会講演予稿集(CD-ROM)  2015/03
• リン酸を含むメソポーラスシリカの合成とその吸着特性  [Not invited]

  武井貴弘, 岡部史岳, 三浦章, 熊田伸弘

  セラミックス基礎科学討論会講演要旨集  2015/01
• CsClフラックスを用いた太陽電池材料Cu(In,Ga)S₂単結晶の育成  [Not invited]

  長尾雅則, 三浦章, 綿打敏司, 武井貴弘, 熊田伸弘, 田中功

  J Flux Growth  2014/12
• 遷移金属を含む層状複水酸化物複合体を用いた有機物変換活性の組成依存性  [Not invited]

  武井貴弘, 計良匡俊, 三谷侑馬, 三浦章, 熊田伸弘

  無機マテリアル学会学術講演会講演要旨集  2014/11
• 水熱反応によるBi⁵⁺を含む新しいビスマス酸化物の合成と結晶構造  [Not invited]

  中村あゆ美, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会関東支部研究発表会講演要旨集  2014/09
• (Co,Ni)Ti(Nb,Ta)₂O₈の合成と結晶構造  [Not invited]

  小池成美, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会関東支部研究発表会講演要旨集  2014/09
• 放射光粉末X線回折によるBaTiO₃系固溶体の結晶構造解析  [Not invited]

  小倉圭介, 熊田伸弘, 武井貴弘, 三浦章, 黒岩芳弘, 森吉千佳子, 馬込英輔

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2014/08
• ナフタレン環架橋ジホスホン酸と銅(II)塩を用いた水熱合成法による無機‐有機ハイブリッドの合成  [Not invited]

  飛世博愛, JULIAN Zapico, 三浦章, 熊田伸弘, 菅原義之

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2014/08
• (Co,Ni)Ti(Nb,Ta)₂O₈の合成と結晶構造  [Not invited]

  小池成美, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2014/08
• 水熱反応によるBi⁵⁺を含む新しいビスマス酸化物の合成と結晶構造  [Not invited]

  中村あゆ美, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2014/08
• 準一次元強相関有機導体α,α’‐(BPDT‐TTF)₂ICl₂の絶縁体状態の研究 I  [Not invited]

  橋本顕一郎, 小林亮太, 井口敏, 黒部貴秀, 米山直樹, 三浦章, 武井貴弘, 熊田信弘, 渡邉真史, 野田幸男, 熊井玲児, 谷口弘三, 佐々木孝彦

  日本物理学会講演概要集  2014/08
• 水熱反応でつくられる新しいビスマス酸化物 ありそうでなかった化合物の合成  [Not invited]

  熊田伸弘, 武井貴弘, 三浦章

  化学  2014/08
• 層状複水酸化物を利用したLi(Ni_xM³⁺_1-x)O₂系層状酸化物の合成  [Not invited]

  布施宏樹, 武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2014/03
• LaO_1-xF_xBiS₂(x~0.23,0.46)単結晶の結晶構造と超伝導特性  [Not invited]

  三浦章, 長尾雅則, 武井貴弘, 綿打敏司, 田中功, 熊田伸弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2014/03
• 1,4‐ビス(ホスホノ)ナフタレンと酢酸銅(II)一水和物を用いた水熱合成法による無機‐有機ハイブリッドの合成  [Not invited]

  飛世博愛, 斉藤ひとみ, ZAPICO Julian, 三浦章, 熊田伸弘, 菅原義之

  日本セラミックス協会年会講演予稿集(CD-ROM)  2014/03
• RO(F)BiS₂系超伝導体単結晶の育成とその超伝導異方性の評価  [Not invited]

  長尾雅則, 出村郷志, 出口啓太, 三浦章, 綿打敏司, 武井貴弘, 高野義彦, 熊田伸弘, 田中功

  日本物理学会講演概要集  2014/03
• 部分分子置換したκ‐(BEDT‐TTF)₂Cu₂(CN)₃における金属相の発現  [Not invited]

  米山直樹, 河野令, 濱田幸司, 佐々木孝彦, 長尾雅則, 田中功, 三浦章, 武井貴弘, 熊田伸弘

  日本物理学会講演概要集  2014/03
• RO(F)BiS₂(R:La,Ce,Nd)超伝導体単結晶のF濃度制御  [Not invited]

  長尾雅則, 出村郷志, 出口啓太, 三浦章, 綿打敏司, 武井貴弘, 高野義彦, 熊田伸弘, 田中功

  応用物理学会春季学術講演会講演予稿集(CD-ROM)  2014/03
• 層状マグネシウムケイ酸塩の水熱合成と特性評価  [Not invited]

  仲沢光司, 三浦章, 武井貴弘, 熊田伸弘

  セラミックス基礎科学討論会講演要旨集  2014/01
• 層状複水酸化物‐ポリアニオン複合体の作製と有機物の酸化特性  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  セラミックス基礎科学討論会講演要旨集  2014/01
• ABX₂層状酸化物及び窒化物における三角柱と八面体配位の調査(A:Li,Na,Mg,Ca,B:Nb,Mo,Ta,W,X:N,O)  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘

  セラミックス基礎科学討論会講演要旨集  2014/01
• ナノポーラス材料の新展開 ソフト化学的手法を用いたナノポーラス材料の合成と細孔の化学修飾  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  表面技術  2014/01
• CsCl系フラックスを用いたBiS₂系超伝導体単結晶の育成  [Not invited]

  長尾雅則, 三浦章, 綿打敏司, 武井貴弘, 熊田伸弘, 田中功, 出村郷志, 出口啓太, 高野義彦

  J Flux Growth  2013/12
• 第4周期遷移金属を部分置換したレピドクロサイト型層状チタン酸塩の作製  [Not invited]

  武井貴弘, 大橋拓磨, 三浦章, 熊田伸弘

  無機マテリアル学会学術講演会講演要旨集  2013/11
• 無機層状化合物(I)層状化合物ナノシートによる電気化学的複合膜の作製  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  J Soc Inorg Mater Jpn  2013/11
• リン酸塩による希土類金属の吸着特性  [Not invited]

  飯塚清晃, 武井貴弘, 三浦章, 熊田伸弘

  日本イオン交換研究発表会講演要旨集  2013/10
• Effect of Teflon Additives on InN Crystal Growth  [Not invited]

  Miura, Akira, Takei, Takahiro, Kumada, Nobuhiro

  2013 MRS-JSAP Joint Symposia  2013/09
• 亜鉛系層状複水酸化物からの酸化亜鉛の合成  [Not invited]

  布施宏樹, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会関東支部研究発表会講演要旨集  2013/09
• 遷移金属を含むレピドクロサイト型層状チタン酸塩(A_(4-n)xTi_1-xMⁿ⁺_xO₂)の作製とその電気化学特性  [Not invited]

  大橋拓磨, 武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会関東支部研究発表会講演要旨集  2013/09
• リン酸塩による希土類金属の吸着特性  [Not invited]

  飯塚清晃, 武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会関東支部研究発表会講演要旨集  2013/09
• (Ba_1‐xBi_x)(Ti_1‐xYb_x)O₃(0≦x≦0.04)の放射光粉末X線回折データを用いた結晶構造解析  [Not invited]

  小倉圭介, 熊田伸弘, 武井貴弘, 三浦章, 黒岩芳弘, 森吉千佳子, 馬込英輔

  日本セラミックス協会関東支部研究発表会講演要旨集  2013/09
• NdO(F)BiS₂超伝導体単結晶のフラックス育成  [Not invited]

  長尾雅則, 出村郷志, 出口啓太, 三浦章, 綿打敏司, 武井貴弘, 高野義彦, 熊田伸弘, 田中功

  応用物理学会秋季学術講演会講演予稿集(CD-ROM)  2013/08
• 遷移金属を含むレピドクロサイト型層状チタン酸塩(A_(4-n)xTi_1-xMⁿ⁺_xO₂)の作製とその電気化学特性  [Not invited]

  大橋拓磨, 武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2013/08
• リン酸塩による希土類金属の吸着特性  [Not invited]

  飯塚清晃, 武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2013/08
• (Na_0.88Ba_0.12)(Nb_0.88Ti_0.12)O₃セラミックスの作製と圧電特性  [Not invited]

  伊藤尚子, 熊田伸弘, 三浦章, 武井貴弘, 和田智志

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2013/08
• 鉄三角格子を持つFe_xWN₂の結晶構造と強磁性  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘, 馬込栄輔, 森吉千佳子, 黒岩芳弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2013/08
• (Ba_1-xBi_x)(Ti_1-xYb_x)O₃(0≦x≦0.04)の放射光粉末X線回折データを用いた結晶構造解析  [Not invited]

  小倉圭介, 熊田伸弘, 武井貴弘, 三浦章, 黒岩芳弘, 森吉千佳子, 馬込英輔

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2013/08
• 先端的セラミックス材料の開発と応用 無機化合物による希土類金属イオンの回収  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  ケミカルエンジニヤリング  2013/06
• 無機化合物による希土類金属の吸着特性  [Not invited]

  飯塚清晃, 十川東香, 武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2013/03
• 遷移金属を含む層状複水酸化物‐ポリアニオン複合体の作製  [Not invited]

  武井貴弘, 計良匡俊, 三浦章, 熊田伸弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2013/03
• 第4周期遷移金属イオンで部分置換したレピドクロサイト型層状チタン酸塩の合成とソフト化学特性  [Not invited]

  大橋拓磨, 武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2013/03
• (Ba_1-xBi_x)(Ti_1-xYb_x)O₃(0≦x≦0.04)の結晶構造解析  [Not invited]

  小倉圭介, 熊田伸弘, 武井貴弘, 三浦章, 和田智志, 黒岩芳弘, 森吉千佳子, 馬込英輔

  日本セラミックス協会年会講演予稿集(CD-ROM)  2013/03
• (Na_0.88Ba_0.12)(Nb_0.88Ti_0.12)O₃セラミックスの作製と圧電特性  [Not invited]

  伊藤尚子, 熊田伸弘, 三浦章, 武井貴弘, 和田智志

  日本セラミックス協会年会講演予稿集(CD-ROM)  2013/03
• NaNH₂を用いた酸化鉄の低温窒化による窒化鉄の合成  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会年会講演予稿集(CD-ROM)  2013/03
• 出発物質の違いによるカルシウムアルミネートの生成温度依存性  [Not invited]

  中村麻穂, 武井貴弘, 三浦章, 熊田伸弘, 荻原清彦

  日本セラミックス協会年会講演予稿集(CD-ROM)  2013/03
• Anion Bonding Chemistry  [Invited]

  Miura, Akira

  SIS2013 (Superconductivity Interdisciplinary Seminar 2013)  2013/03
• 溶融塩を用いたATiO₃(A:Mg,Ca,Sr,Ba)の低温合成  [Not invited]

  熊田伸弘, 伊藤尚子, 三浦章, 武井貴弘

  セラミックス基礎科学討論会講演要旨集  2013/01
• 第一原理計算と放射光を用いた岩塩型NbX(X=C,N,O)の結晶構造と化学結合に関する研究  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘, 和田智志, 馬込栄輔, 森吉千佳子, 黒岩芳弘

  セラミックス基礎科学討論会講演要旨集  2013/01
• 層状金属リン酸塩と導電性高分子の電気化学的複合化とその電気化学特性に関する研究  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  無機リン化学討論会講演予稿集  2013
• セピオライトの特性とその応用  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘

  耐火物  2013/01
• 石灰硫黄合剤の廃棄物を用いたカルシウムアルミネートの合成  [Not invited]

  武井貴弘, 中村麻穂, 三浦章, 熊田伸弘

  無機マテリアル学会学術講演会講演要旨集  2012/11
• (Li_0.12Na_0.88)NbO₃系固溶体の合成と誘電特性  [Not invited]

  伊藤尚子, 熊田伸弘, 三浦章, 武井貴弘, 和田智志

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2012/09
• 遷移金属を含むLDHの剥離‐再析出法によるナノ構造制御  [Not invited]

  武井貴弘, 計良匡俊, 三浦章, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2012/09
• 農薬副生成物(亜硫酸カルシウム)からのカルシウムアルミネートの低温合成  [Not invited]

  中村麻穂, 武井貴弘, 三浦章, 熊田伸弘, 荻原清彦

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2012/09
• 無機化合物による希土類金属イオンの回収  [Not invited]

  熊田伸弘, 三浦章, 武井貴弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2012/09
• NaNH₂フラックスを用いたLiInO₂とMn₂O₃の低温窒化  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)  2012/09
• LiInO₂の低温窒化によるInN結晶の合成と評価  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘

  応用物理学会学術講演会講演予稿集(CD-ROM)  2012/08
• 第4周期遷移金属を含有する層状複水酸化物の作製と吸着特性  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  無機マテリアル学会学術講演会講演要旨集  2012/06
• フッ素化層状ペロブスカイトナノシート‐ポリアニリン複合配向膜の作製と電気化学特性評価  [Not invited]

  武井貴弘, 村木七江, 三浦章, 熊田伸弘

  粉体粉末冶金協会講演概要集  2012/05
• 水熱反応によるBiFeO₃微粒子の合成  [Not invited]

  小林雅, 熊田伸弘, 三浦章, 米崎功記, 武井貴弘, 藤井一郎, 和田智志

  日本セラミックス協会年会講演予稿集  2012/03
• 新規ニオブ層状酸化物Mg_0.5NbO₂の結晶構造  [Not invited]

  三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会年会講演予稿集  2012/03
• (Li_0.12Na_0.88)NbO₃系固溶体の合成と誘電特性  [Not invited]

  伊藤尚子, 熊田伸弘, 三浦章, 米崎功記, 武井貴弘, 和田智志

  日本セラミックス協会年会講演予稿集  2012/03
• 遷移金属を含む層状複水酸化物のソフト化学処理と多孔体への応用  [Not invited]

  武井貴弘, 三浦章, 熊田伸弘

  日本セラミックス協会年会講演予稿集  2012/03
• Bi(Fe_1/4Ni_3/8Ti_3/8)O₃‐BaTiO₃系セラミックスの合成と誘電特性  [Not invited]

  小林雅, 熊田伸弘, 三浦章, 米崎功記, 武井貴弘, 藤井一郎, 和田智志

  セラミックス基礎科学討論会講演要旨集  2012/01
• 有色廃ビンガラスの水熱処理による高機能化  [Not invited]

  太田宏章, 武井貴弘, 三浦章, 米崎功記, 熊田伸弘, 高橋浩幸

  セラミックス基礎科学討論会講演要旨集  2012/01
• 水熱反応による5価のビスマスを含むCdBi₂O₆の合成  [Not invited]

  熊田伸弘, 三浦章, 米崎功記, 武井貴弘, 和田智志, 藤井一郎, 西本俊介, 亀島欣一, 三宅通博, 黒岩芳弘

  セラミックス基礎科学討論会講演要旨集  2012/01
• 亜硫酸カルシウムの物質変換による機能性材料の合成  [Not invited]

  武井貴弘, 今沢直人, 三浦章, 米崎功記, 熊田伸弘

  セラミックス基礎科学討論会講演要旨集  2012/01
• Euを添加したOlgite型リン酸塩化合物の蛍光特性  [Not invited]

  米崎功記, 松田千寛, 三浦章, 武井貴弘, 熊田伸弘

  セラミックス基礎科学討論会講演要旨集  2012/01
• フッ素化層状ペロブスカイト型化合物ナノシートを用いた無機有機複合膜の作製  [Not invited]

  村木七江, 武井貴弘, 三浦章, 米崎功記, 熊田伸弘

  セラミックス基礎科学討論会講演要旨集  2012/01
• セピオライト複合体シートにおける希土類イオンの吸脱着特性  [Not invited]

  三浦章, 古屋太陽, 武井貴弘, 熊田伸弘

  日本イオン交換研究発表会講演要旨集  2012
• 無機化合物による希土類金属の吸着特性  [Not invited]

  飯塚清晃, 十川東香, 武井貴弘, 三浦章, 熊田伸弘

  日本イオン交換研究発表会講演要旨集  2012
• LiNbO₂とKCl‐LiCl‐MgCl₂フラックスとの反応による新規層状酸化物の生成  [Not invited]

  三浦章, 米崎功記, 武井貴弘, 熊田伸弘

  J Flux Growth  2011/12
• 無機繊維複合体シートを用いた希土類金属イオンの吸着特性  [Not invited]

  古屋太陽, 十川東香, 三浦章, 米崎功記, 武井貴弘, 熊田伸弘

  日本イオン交換研究発表会講演要旨集  2011/11
• 無機化合物を用いた希土類金属イオンの回収  [Not invited]

  十川東香, 古屋太陽, 三浦章, 米崎功記, 武井貴弘, 熊田伸弘

  日本イオン交換研究発表会講演要旨集  2011/11
• 中国産セピオライトの耐薬品性  [Not invited]

  三浦章, 仲沢光司, 米崎功記, 武井貴弘, 熊田伸弘, 木野村暢一, 大木亮作, 越山博喜

  無機マテリアル学会学術講演会講演要旨集  2011/11
• Bi(Fe_1/4Ni_3/8Ti_3/8)O₃‐BaTiO₃系セラミックスの合成と誘電特性  [Not invited]

  小林雅, 熊田伸弘, 三浦章, 米崎功記, 武井貴弘, 藤井一郎, 和田智志

  日本セラミックス協会関東支部研究発表会講演要旨集  2011/09
• 石灰硫黄合剤の副生成物である亜硫酸カルシウムからのハイドロキシアパタイトの合成  [Not invited]

  武井貴弘, 三浦章, 米崎功記, 熊田伸弘, 荻原清彦

  無機リン化学討論会講演予稿集  2011/09
• Na₂MMg(PO₄)₂(M:Ca,Sr,Ba):Eu²⁺の蛍光特性  [Not invited]

  松田千寛, 米崎功記, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会関東支部研究発表会講演要旨集  2011/09
• 水熱反応による新しいリン酸ジルコニウムの合成と結晶構造解析  [Not invited]

  熊田伸弘, 武井貴弘, 米崎功記, 三浦章, 木野村暢一

  無機リン化学討論会講演予稿集  2011/09
• 有色廃ビンガラスの水熱処理による高機能化  [Not invited]

  太田宏章, 武井貴弘, 三浦章, 米崎功記, 熊田伸弘, 木野村暢一, 高橋浩幸

  日本セラミックス協会関東支部研究発表会講演要旨集  2011/09
• 酸化還元反応を用いた酸化マンガン‐導電性高分子ハイブリッドの作製と電気化学特性  [Not invited]

  武井貴弘, 三浦章, 米崎功記, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集  2011/09
• A₂MMg(PO₄)₂(A:Li,Na,Ca,M:Ca,Sr,Ba):Eu²⁺の合成と蛍光特性  [Not invited]

  松田千寛, 米崎功記, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会秋季シンポジウム講演予稿集  2011/09
• 第一原理計算を用いた新規デラフォサイト窒化物の探索とその合成  [Not invited]

  三浦章, 米崎功記, 武井貴弘, 熊田伸弘, WESSEL Michael, DRONSKOWSKI Richard

  日本セラミックス協会秋季シンポジウム講演予稿集  2011/09
• 水熱反応による新しい無機化合物の創製  [Not invited]

  熊田伸弘, 武井貴弘, 米崎功記, 三浦章, DONG D

  日本セラミックス協会秋季シンポジウム講演予稿集  2011/09
• Bi(Fe_1/4Ni_3/8Ti_3/8)O₃‐BaTiO₃系セラミックスの合成と誘電特性  [Not invited]

  小林雅, 熊田伸弘, 三浦章, 米崎功記, 武井貴弘, 藤井一郎, 和田智志

  日本セラミックス協会秋季シンポジウム講演予稿集  2011/09
• 水熱処理による有色廃ビンガラスの高機能化  [Not invited]

  太田宏章, 武井貴弘, 三浦章, 米崎功記, 熊田伸弘, 木野村暢一

  無機マテリアル学会学術講演会講演要旨集  2011/06
• LiTaN₂の計算手法による探索と合成  [Not invited]

  三浦章, 米崎功記, 武井貴弘, 熊田伸弘, WESSEL Michael, DRONSKOWSKI Richard

  日本セラミックス協会年会講演予稿集  2011/03
• 酸化還元反応による酸化マンガン―導電性高分子複合体の合成と電気化学特性  [Not invited]

  武井貴弘, 三浦章, 米崎功記, 熊田伸弘, 木野村暢一

  日本セラミックス協会年会講演予稿集  2011/03
• Bi(Fe_1/4Ni_3/8Ti_3/8)O₃‐BaTiO₃系セラミックスの合成と誘電特性  [Not invited]

  小林雅, 熊田伸弘, 三浦章, 米崎功記, 武井貴弘, 藤井一郎, 和田智志

  日本セラミックス協会年会講演予稿集  2011/03
• チタン酸バリウム含有結晶化ガラスの作製  [Not invited]

  松田千寛, 米崎功記, 三浦章, 武井貴弘, 熊田伸弘

  日本セラミックス協会年会講演予稿集  2011/03
• Ga₂O₃の炭素熱還元窒化法によるGaN結晶成長に関する研究  [Not invited]

  横山大輝, 三浦章, 嶋田志郎

  セラミックス基礎科学討論会講演要旨集  2010/01
• Deintercalation of iron from FeWN2  [Not invited]

  Akira Miura, Francis DiSalvo

  The 238th National Meeting & Exposition of the American Chemical Society (ACS)  2009/08
• 高濃度の酸素を含むGaN単結晶の育成とその特性  [Not invited]

  三浦章, 嶋田志郎, 関口隆史, 横山政昭, 溝淵文章, 北村寿朗

  日本セラミックス協会秋季シンポジウム講演予稿集  2007/09
• 炭素熱還元窒化法による高輝度ZnドープGaN結晶の作製とCL特性  [Not invited]

  大谷浩輝, 三浦章, 嶋田志郎, 関口隆史, 横山政昭, 溝淵文章

  応用物理学会学術講演会講演予稿集  2007/09
• 連続供給されたGa₂O₃の炭素熱還元窒化によって育成したGaN結晶の評価  [Not invited]

  三浦章, 嶋田志郎, 関口隆史, 横山政昭, 溝淵文章, 北村寿朗, 中島信一

  応用物理学会学術講演会講演予稿集  2007/09
• 炭素熱還元窒化法による高輝度GaN:Zn結晶の作製  [Not invited]

  大谷浩輝, 三浦章, 嶋田志郎

  日本化学会北海道支部研究発表会講演要旨集  2007/07
• 連続原料供給されたGa₂O₃の炭素熱還元窒化によるGaN結晶育成  [Not invited]

  三浦章, 嶋田志郎, 関口隆史, 横山政昭, 溝淵文章

  応用物理学関係連合講演会講演予稿集  2007/03
• Ga₂O₃とGeO₂の同時炭素熱還元窒化による高輝度GeドープGaN結晶粉末の作製とその評価  [Not invited]

  三浦章, 三浦洋子, 嶋田志郎, 関口隆史, 横山政昭, 溝淵文章

  応用物理学関係連合講演会講演予稿集  2007/03
• 炭素熱還元窒化法によるGaNバルク体結晶の成長とその特性評価  [Not invited]

  嶋田志郎, 三浦章, 関口隆史, 横山政昭, 溝淵文章

  結晶成長国内会議予稿集  2007
• Ga₂O₃の熱炭素還元窒化による高温でのGaN結晶成長  [Not invited]

  三浦章, 嶋田志郎, 関口隆史

  日本結晶成長学会誌  2006/11
• 炭素熱還元反応を利用したGaN結晶の合成  [Not invited]

  三浦章, 嶋田志郎

  熱測定討論会講演要旨集  2006/09
• Ga₂O₃の炭素還元窒化法によるミリメーターサイズのGaN結晶の成長とその評価  [Not invited]

  三浦章, 嶋田志郎, 関口隆史

  応用物理学会学術講演会講演予稿集  2006/08

Teaching Experience

Solid-state ChemistrySolid-state Chemistry
Solid-state ChemistrySolid-state Chemistry School of Engineering, Hokkaido University

Association Memberships

• THE CHEMICAL SOCIETY OF JAPAN   JAPAN SOCIETY OF ION EXCHANGE   THE ELECTROCHEMICAL SOCIETY OF JAPAN   THE CERAMIC SOCIETY OF JAPAN   

Research Projects

• Exploring new metastable phases via different diffusion rates

  Japan Science and Technology Agency：Sakigake

  Date (from‐to) : 2021/10 -2025/03 

  Author : Akira Miura
• Emerging new ternary nitride materials using amide source

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2021/04 -2024/03 

  Author : 三浦 章, 長尾 雅則

   

  本計画では、独自の合成技術であるアミド粉末を用いた自己燃焼反応により、従来法では得ることが困難であった新規三元系窒化物を合成する。化学的安定性を備えた4d、5d遷移金属窒化物と、化学的安定性は乏しいが多彩な物性発現が期待できる3d遷移金属窒化物または4f希土類金属窒化物を組み合わせ、新規電気化学触媒および新規磁性材料・超伝導材料を創造することを目指す。 初年度は、酸性水溶液またはアルカリ性水溶液中の安定性に優れたモリブデン窒化物およびアルカリ性水溶液中で安定である窒化マンガンを母体とし、その中に希土類元素を導入することを目指し、合成実験を行った。モリブデン窒化物中には希土類元素は導入は困難であった。その一方、マンガン窒化物中へ微量の希土類元素の導入されたことが結晶構造解析および電子顕微鏡観察によって明らかになった。また、希土類イオンをドープしたマンガン窒化物の磁化率の温度依存性を測定したところ、マンガン窒化物とはことなる磁気転移をしめした。このことは、希土類元素のドーピングによって窒化マンガンの電子状態が変化したことを示唆している。アルカリ性水溶液中で電気化学測定を行い酸素還元触媒能を評価したところ、希土類ドープマンガン窒化物は希土類量を調整することで触媒能が向上することが明らかになった。X線光電子分光法（XPS）測定によって、窒化物表面の水酸化物吸着能が変化することが確認され、それによって触媒能が変化したと考察した。
• Exploring new layered compounds by designing synthesis reactions

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))

  Date (from‐to) : 2020/10 -2024/03 

  Author : 三浦 章, 藤岡 正弥, 後藤 陽介

   

  本研究は、日本・アメリカ・イギリスの若手研究者による国際共同研究であり、論理的な合成反応設計に基づく多元系層状化合物の探索により新規エネルギー材料の創出を目指すものである。 本年度は論理的な合成設計の第一歩として、ミシガン大学のSun博士らと既知化合物の固相合成反応過程を調査を行った。具体的には1987年に発見された高温超伝導体YBa2Cu3O6+x（通称YBCO(ワイビーシーオー)）の合成反応の調査を行った。YBa2Cu3O6+xは，酸化イットリウム(Y2O3)，炭酸バリウム(BaCO3), 酸化銅(CuO)の粉末混合物を800-1000度に加熱することで合成さる。炭酸バリウムを用いた合成反応では，YBCOの合成に十時間以上の長時間の加熱が必要であった。第一原理計算は炭酸バリウムと他の化合物の反応エネルギーは小さいことを示し，放射光X線回折でも短時間では反応が進行しないことが確かめられた。一方，炭酸バリウム(BaCO3)の代わりに過酸化バリウム(BaO2)に置き換えると，30分以内にYBCOが生成した。過酸化バリウムを用いた反応における最初の反応は，熱力学的駆動力が最も大きい粉末の組み合わせから反応が進行することが明らかになった。実際に，過酸化バリウムと酸化銅の組み合わせで反応が進行することが，その場X線回折と電子顕微鏡観察で確かめられた。高温でのYBCOが生成する反応では反応エネルギーが小さく，物質拡散が重要になる。バリウム，銅と酸素と構成される中間生成物が溶融して酸化イットリウムと反応することで，YBCOが短時間で生成することが明らかになりました。このように複雑なセラミックスを合成する反応を，２相間の逐次的な反応に分けて考えることで、固相反応全体を理解することが可能になった。
• Synthesis of new mix-anion compounds by rapid self-combustion reactions

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

  Date (from‐to) : 2019/04 -2021/03 

  Author : 三浦 章

   

  本研究では、我々が開発した塩化物とナトリウムアミドによる大きな熱力学的駆動力を用いた短時間の新規無機化合物合成法を基盤に、高速な反応で複雑な組成の組み合わせを持つ複合アニオン化合物をはじめとする無機物質を合成することを目指した。塩化物とナトリウムアミドを反応させることで、窒化物や酸窒化物をはじめとするさまざまな物質が短時間で生成することが明らかになった。合成した化合物を、ＸＲＤ、ＳＥＭ、酸素窒素分析で調査し、合成した化合物の酸素還元能を調査した。 最終年度では、高速で反応が進行する液相合成や固相合成にも範囲を広げ、新規材料合成法の開発を行った。Li2SやP2S5、LiClなどを出発原料とし、Li6PS5Clなどの複合アニオン化合物を、有機溶媒中でマイクロ波加熱することで短時間で合成する方法を見出した。これらの化合物の交流インピーダンス測定を行い硫化物電解質として使用できることを確認した。さらに、複合アニオン化合物を作るうえでは、複数の粉末からの固相合成は基本的な合成法であるが、合成過程は明らかではない。そこで、大きな熱力学的駆動力がある３種類の前駆体粉末の混合物を数百度で加熱することで短時間で進行するセラミックスの固相合成反応過程を、放射光X線回折、電子顕微鏡と第一原理計算を用いて調べた。逐次的に進行する短時間での固相合成過程を実験的に直接観測し、出発原料の様々な組合せの反応エネルギーを計算することで、反応過程の駆動力を理解した。複合アニオン化合物などのセラミックス材料は複雑な組成をもつものが多く、その合成過程は明らかではなく、試行錯誤によって合成されてきた。固相合成過程を論理的に理解することで、複雑な組成をもつ様々な複合アニオン化合物の合成反応を効率的に設計することが期待できる。
• Low temperature synthesis of nitride thin films through a reaction between oxide gel films and molten salts

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2017/04 -2020/03 

  Author : TADANAGA Kiyoharu

   

  In this study, new processes to obtain thin films of metal nitrides or metal oxynitrides at rather mild conditions have been studied. Gel films prepared by the sol-gel process were reacted with a liquid phase of a low-temperature molten salt containing nitrogen, or heat-treated with various nitrogen-containing compounds. Oxide gel films were heat-treated in an electric furnace, where urea was placed upstream, under a nitrogen flow. Cu3N or TaON thin films were obtained by this heat-treatment with copper oxide or tantalum oxide thin films prepared by a liquid phase process.
• Low-temperature synthesis of oxynitrides for development of new functional materials

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)

  Date (from‐to) : 2017/04 -2020/03 

  Author : MIURA Akira

   

  This reserch project aims to propose the new synthesis method for oxynitrides without long heat treatment, and to emerge new functional materials. Our achievement includes the combustion reaction from chloride, oxyhydride and amide to form BaNbO2N and BaTaO2N. Mn incorporation into Mo2N framework changed its electronic structure and improved the catalytic activity toward oxygen reduction reaction.
• Low temperature synthesis of nitride thin films through a reaction between oxide gel films and molten salts

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2017/04 -2020/03 

  Author : TADANAGA Kiyoharu

   

  In this study, new processes to obtain thin films of metal nitrides or metal oxynitrides at rather mild conditions have been studied. Gel films prepared by the sol-gel process were reacted with a liquid phase of a low-temperature molten salt containing nitrogen, or heat-treated with various nitrogen-containing compounds. Oxide gel films were heat-treated in an electric furnace, where urea was placed upstream, under a nitrogen flow. Cu3N or TaON thin films were obtained by this heat-treatment with copper oxide or tantalum oxide thin films prepared by a liquid phase process.
• Low-Temperature Synthesis and Rational Design of Nitrides and Oxynitrides for Novel Functional Material Development

  Ministry of Education, Culture, Sports, Science and Technology：KAKENHI WakateA

  Date (from‐to) : 2017/04 -2020/03 

  Author : Miura, Akira
• Clarification of the correlation between functionality and chemical pressure in BiCh2-based compounds

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2016/04 -2019/03 

  Author : MIZUGUCHI Yoshikazu

   

  We have investigated chemical pressure effects on local structure, superconducting properties, and thermoelectric properties of BiCh2-based layered compounds. According to the obtained concept for BiCh2-based material design, new superconductors, (Eu,RE)FBi(S,Se)2, (La,Ce)OBiSSe, and (Ce,Pr)OBiS2, were discovered. Furthermore, La2O2Bi3AgS6 with a four-layer-type superconducting layer was discovered. From isotope effect, we found that BiCh2-based superconductors can be categorized into unconventional superconductors. We have also developed related layered compounds with InS2-type and SbSe2-type conducting layers.
• 自己燃焼反応による新規モリブデン窒化物の探索

  公益財団法人豊田理化学研究所：豊田理研スカラー

  Date (from‐to) : 2018/04 -2019/03 

  Author : 三浦 章
• BiCh2系層状化合物における機能性発現と化学圧力効果の相関解明

  Ministry of Education, Culture, Sports, Science and Technology：KAKENHI KibanB

  Date (from‐to) : 2016/04 -2019/03 

  Author : Mizuguchi, Yoshikazu
• Synthesis and characterization of mixed anion compounds with controlled Bi bonds

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

  Date (from‐to) : 2015/04 -2017/03 

  Author : MIURA AKIRA

   

  Layered mixed anion compounds, such as LaOBiS2, have been intensively studied since they have high flexibility for designing properties by changing composed anions. The aims of this research are 1) control properties by tuning chemical bond between Bi and S/Se and 2)producing new two-dimensional nanosheets by exfoliation. Research accomplishment includes the correlation between rare earth elements and superconductive transition, and the relationship between chemical pressure of the chmical bond of Bi-S/Se and superconductive transition temperature. The synthesis of LaOBiS2 nanosheets have been successful. We discover new layered oxysulfides including antimony and indium.
• Preparation and Characterization of Nes Superconductive Bismuth Oxides by Hydrothermal Reaction

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

  Date (from‐to) : 2014/04 -2017/03 

  Author : KUMADA Nobuhiro

   

  New superconductive bismuth oxides, (K1.00)(Ba1.00)3(Bi0.89Na0.11)4O12, (Ba0.62K0.38)(Bi0.92Mg0.08)O3 and (Ba0.83K0.17)(Bi0.54Pb0.46)O3 were prepared by hydrothermal reaction. The first one had a double perovskite-type structure with Tc = 31.5K and the second and third ones had a simple perovskite-type structure. The Tc of the second and third ones were 30 and 22.8k, respectively. Their crystal structures were refined by Rietveld method using synchrotron X-ray powdewr diffraction data.
• 層状炭化物の低温窒化による窒化チタンシートの合成

  日本板硝子材料工学助成会：研究助成

  Date (from‐to) : 2016/04 -2017/03 

  Author : 三浦 章
• NaNH2融液を用いた窒化物ナノ粒子の合成

  矢崎科学技術振興記念財団：国際交流援助

  Date (from‐to) : 2016/06 -2016/07 

  Author : 三浦 章
• Ta5N6の結晶構造および電子構造

  日本科学協会：海外発表促進助成

  Date (from‐to) : 2015/08 -2015/09 

  Author : 三浦 章
• Development of new low-temperature synthesis method for nitrides

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

  Date (from‐to) : 2013/04 -2015/03 

  Author : MIURA Akira

   

  A new approach to synthesize nitrides from oxides using sodium amide was investigated in order to reduce environmental cost for synthesis of nitrides. Manganese, iron, copper and indium nitrides were synthesized from oxides. This developed method has the advantages of low reaction temperature, reduced consumption of ammonia, employing nonspecialized equipments for synthesis of submicron-sized nitride powder from oxides. The optical and magnetic properties of the products were characterized.
• 色つき水晶の水熱合成による教育研究活動

  日教弘会山梨支部：日教弘会山梨支部奨励金

  Date (from‐to) : 2011/07 -2012/03 

  Author : 三浦 章
• Investigation of interlayer reactions in nitrides/carbodiimides by experimental and computational approaches

  Alexander von Humboldt Foundation：Alexander von Humboldt Fellowship

  Date (from‐to) : 2010/02 -2010/11 

  Author : Miura, Akira
• Growth and Characterization of GaN bulk crystals by carbothermal reduction and nitridation method

  Clark Foundation：博士後期課程研究助成

  Date (from‐to) : 2007/04 -2007/12 

  Author : Miura, Akira
• Synthesis and Properties of GaN:Sn crystals by carbothermal reduction and nitridation method

  The Japan Science Society：Sasagawa Reserach Fellowship

  Date (from‐to) : 2006/07 -2007/03 

  Author : Miura, Akira

Industrial Property Rights

• 特願2015-213703:電極活物質、電池及び電極活物質の製造方法  2015年/10

  三浦章, 忠永清治
• 特願2013-053787:ガラスからメソポーラスシリカを製造する方法  2013年/03

  武井貴弘, 熊田伸弘, 三浦章, 高橋浩幸

Social Contribution

• 北海道大学化学系への二日体験入学

  Date (from-to) : 2019/07/30-2019/07/31

  Role : Lecturer
• 北海道大学化学系への二日体験入学

  Date (from-to) : 2018/07/30-2018/07/31

  Role : Lecturer
• さっぽろサイエンスフェスタin北大

  Date (from-to) : 2018/03/04

  Role : Demonstrator

  Sponser, Organizer, Publisher  : 北海道大学女性研究者支援室
• 北海道大学化学系への二日体験入学

  Date (from-to) : 2017/08/04

  Role : Lecturer
• 北海道大学工学部オープンキャンパス

  Date (from-to) : 2016/08

  Role : Lecturer
• 「結晶材料の新展開」 文部科学省ミュージアム「情報ひろば」企画展示

  Date (from-to) : 2014/08/01-2014/08/31

  Role : Organizing member

  Sponser, Organizer, Publisher  : 山梨大学
• センター見学

  Date (from-to) : 2011-2014

  Role : Organizing member

  Sponser, Organizer, Publisher  : 山梨大学 クリスタル科学研究センター
• 一日体験化学教室

  Date (from-to) : 2010-2014

  Role : Lecturer

  Sponser, Organizer, Publisher  : 山梨大学
• クリスタル科学研究センター公開

  Date (from-to) : 2011-2013

  Role : Organizing member

  Sponser, Organizer, Publisher  : 山梨大学 クリスタル研究センター
• クリスタル体験講座

  Date (from-to) : 2011-2013

  Role : Demonstrator

  Sponser, Organizer, Publisher  : 山梨大学 クリスタル研究センター

Others

• 2019/11 -2019/11 6大学助教を対象とした リーダー的素養を学び合う交流会（助教交流会）
• 2017/07 -2017/07 安全保障輸出管理FD
• 2016/11 -2016/11 アクティブ型授業への転換を目指して
• 2016/08 -2016/08 北海道大学工学部オープンキャンパス
• 2016/08 -2016/08 研究者のためのスキルアップセミナー

  「外部資金獲得のためのレイアウトとデザイン」についてのスキルアップセミナーを受講した。
• 2015/09 -2015/09 第27回北海道大学教育ワークショップ(2日間)

  シラバスの構成法を中心としたワークショップを受講した。
• 2015/03 -2015/03 Nature Masterclasses受講（2日間）

  Nature Masterclassesを受講し、論文執筆手法を学習した。
• 2014/10 -2014/10 ファシリテーション講習を受講（3日間）

  ファシリテーションの基礎技術を習得した。