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Fushimi Koji

Faculty of Engineering　Applied Chemistry　Functional Materials ChemistryAssociate Professor
Institute for the Promotion of Business-Regional CollaborationAssociate Professor

Researcher basic information

■ Degree
  • Dr.Eng., 12/2001, Hokkaido University, Sapporo, Hokkaido University
■ URL
researchmap URLホームページURL■ Various IDs
J-Global ID■ Research Keywords and Fields
Research Keyword
  • 表面物理化学
  • 腐食科学
  • 電気化学
  • Surfacial physical chemistry
  • Corrosion Science
  • Electrochemistry
Research Field
  • Nanotechnology/Materials, Material processing and microstructure control, 腐食防食
■ Educational Organization

Career

■ Career
Career
  • Jun. 2015 - Present
    Hokkaido University, Faculty of Engineering, Associate Professor
  • Apr. 2010 - May 2015
    Hokkaido University, Faculty of Engineering, Associate Professor
  • Apr. 2008 - Mar. 2010
    Hokkaido University, Faculty of Engineering, Associate Professor
  • Apr. 2007 - Mar. 2008
    Hokkaido University, Graduate School of Engineering, Assistant Professor
  • Apr. 2005 - Mar. 2007
    Hokkaido University, Graduate School of Engineering, Research Associate
  • Apr. 1995 - Mar. 2005
    Hokkaido University, Graduate School of Engineering, Research Associate
  • Apr. 2002 - Jul. 2003
    Max-Planck-Institute for Iron Research, Germany, Visiting Researcher
  • Apr. 1992 - Jul. 1995
    Toyo Seikan Kaisya, Dept. R&D, Toyo Seikan Group, Researcher
Educational Background
  • 1992, Hokkaido University, 工学研究科, 応用化学専攻, Japan
  • 1992, Hokkaido University, Graduate School, Division of Engineering
  • 1990, Hokkaido University, School of Engineering, Department of Applied Chemistry, Japan
  • 1990, Hokkaido University, Faculty of Engineering
Committee Memberships
  • Mar. 2025 - Present
    電気化学会, 腐食専門委員会長, Society
  • Feb. 2025 - Present
    表面技術協会, 理事（国際交流担当委員会副委員長）, Society
  • Jan. 2025 - Present
    腐食防食学会, 北海道支部長, Society
  • Mar. 2023 - Feb. 2026
    日本鉄鋼協会, 「水素侵入と水素捕捉に関する革新的評価技術」研究会主査, Society
  • Jan. 2023 - Dec. 2024
    表面技術協会, 北海道支部長, Society
  • Mar. 2021 - Feb. 2023
    日本鉄鋼協会, 材料の組織と特性部会「鋼材腐食水素侵入に関する評価技術の新展開」フォーラム座長, Society
  • Feb. 2019 - Feb. 2021
    腐食防食学会, 理事, Society
  • 2010 - Feb. 2017
    腐食防食学会, 出版委員会委員長, Society
  • 2009 - 2010
    表面技術協会, 評議員, Society
  • 2004 - 2005
    腐食防食協会, 編集委員, Society
  • 2003 - 2005
    表面技術協会, 評議員, Society
  • 1996
    表面技術協会, 北海道支部幹事, Society
  • 1996
    腐食防食学会, 北海道支部幹事, Society
  • 1996
    電気化学会, 北海道支部幹事, Society

Research activity information

■ Awards
  • May 2022, Japan Society of Corrosion Engineering, The JSCE Award for Scientific Contribution
    金属材料表面のその場観察のための微小電気化学測定法の開発と腐食防食への適用
  • Mar. 2018, The Iron and Steel Institute of Japan, The Best Year's Paper Award, Sawamura Award
    FUSHIMI Koji, Hydrogen Permeation into a Carbon Steel Sheet Observed by a Micro-capillary Combined with a Devanathan-Stachurski Cell, ISIJ International, Vol.56(2016), No.3, pp.431-435.
  • May 2017, 公益社団法人腐食防食学会, 平成29年度論文賞
    河野崇史;石井知洋;梶山浩志;木村光男;伏見公志, ステンレス鋼の溶接ヒートティント部の局所電気化学挙動
  • May 2002, 社団法人腐食防食協会, 平成14年度進歩賞
    伏見公志
■ Papers
■ Other Activities and Achievements
■ Books and other publications
  • Electrochemistry for Corrosion Fundamentals
    Toshiaki Ohtsuka; Atsushi Nishikata; Masatoshi Sakairi; Koji Fushimi, 6. Micro-electrochemical Approach for Corrosion Study
    Springer, 2018, [Joint work]
  • 機器分析化学
    伏見 公志, 13 腐食現象への走査型電気化学顕微鏡でのアプローチ
    朝倉書店, 2004, [Joint work]
■ Lectures, oral presentations, etc.
  • Luminescence properties of lanthanide coordinantion polymers with 3-D network structures
    Kohei Miyata; Takayuki Nakanishi; Atsushi Kobayashi; Masako Kato; Koji Fushimi; Yasuchika Hasegawa
    Challenges in Advanced Chemistry of Asia, 2012 HU-NU-SNU-NIMS/MANA Joint Symposium, 06 Dec. 2012, English, Poster presentation
    Sapporo, Japan, [International presentation]
  • EuS Nano-assembles Attached with Naphthalenedithiols
    Akira Kawashima; Takayuki Nakanishi; Koji Fushimi; Yasuchika Hasegawa
    Challenges in Advanced Chemistry of Asia, 2012 HU-NU-SNU-NIMS/MANA Joint Symposium, 06 Dec. 2012, English, Poster presentation
    Sapporo, Japan, [International presentation]
  • Active and Passive State of Iron in Sulfuric Acid Measured by a Micro-capillary-cell
    Yu Takabatake; Koji Fushimi; Takayuki Nakanishi; Yasuchika Hasegawa
    Challenges in Advanced Chemistry of Asia, 2012 HU-NU-SNU-NIMS/MANA Joint Symposium, 06 Dec. 2012, English, Poster presentation
    Sapporo, Japan, [International presentation]
  • Formation of area and thickness controlled porous type aluminum anodic oxide films by Sf-MDC
    M. Sakairi; T. Yamaguchi; T. Murata; K. Fushimi
    PRiME2012, Oct. 2012, English, Oral presentation
    Honolulu, USA, [International presentation]
  • Stability of Passive State of Iron Single Grains in Sulphuric Acid Measured by a Micro-capillary-cell
    Y. Takabatake; K. Fushimi; T. Nakanishi; Y. Hasegawa
    63nd Annual Meeting of the International Society of Electrochemistry, 19 Aug. 2012, English, Poster presentation
    Prague, Czech Republic, [International presentation]
  • Growth and Breakdown of Anodic Oxide Film on Titanium Observed by Ellipsometric Microscopy
    K. Fushimi; K. Kurauchi; T. Nakanishi; Y. Hasegawa; T. Ohtsuka
    63nd Annual Meeting of the International Society of Electrochemistry, 19 Aug. 2012, English, Oral presentation
    Prague, Czech Republic, [International presentation]
  • Grain-dependent Passivity of Iron in Sulphuric Acid Using Micro-capillary Cell
    Y. Takabatake; K. Fushimi; T. Nakanishi; Y. Hasegawa
    9th International Symposium on Electrochemical Micro & Nanosystem Technology, 15 Aug. 2012, English, Poster presentation
    Linz, Austria, [International presentation]
  • Micro-electrode techniques for corrosion analyses
    K. Fushimi; Y. Takabatake; T. Nakanishi; Y. Hasegawa
    9th International Symposium on Electrochemical Micro & Nanosystem Technology, 15 Aug. 2012, English, Keynote oral presentation
    Linz, Austria, [Invited], [International presentation]
  • Magneto-optical properties of Tb(III) clusters
    Y. Suzuki; Y. Doi; Y. Hinatsu; H. Ito; T. Nakanishi; K. Fushimi; Y. Hasegawa
    19th International SPACC symposium, The society of pure and applied coordination chemistry (SPACC), 03 Aug. 2012, English, Poster presentation
    Sapporo, Japan, [International presentation]
  • Luminescent Eu(III) complex with asymmetric coordination structure by monodentate phosphine oxide
    T. Ohkubo; T. Nakanishi; K. Fushimi; Y. Hasegawa
    19th International SPACC symposium, The society of pure and applied coordination chemistry (SPACC), 03 Aug. 2012, English, Poster presentation
    Sapporo, Japan, [International presentation]
■ Syllabus
  • 総合化学特論Ⅰ (Modern Trends in Physical and Material Chemistry), 2024年, 修士課程, 工学院
  • 総合化学特論Ⅰ(Modern Trends in Physical and Material Chemistry), 2024年, 修士課程, 総合化学院
  • 大学院共通授業科目（一般科目）：自然科学・応用科学, 2024年, 修士課程, 大学院共通科目
  • 応用物質化学（界面電子化学）, 2024年, 修士課程, 総合化学院
  • 先端総合化学特論Ⅰ, 2024年, 博士後期課程, 総合化学院
  • 総合化学特論Ⅰ (Modern Trends in Physical and Material Chemistry), 2024年, 博士後期課程, 工学院
  • 電子材料化学, 2024年, 学士課程, 工学部
  • 応用化学学生実験Ⅰ, 2024年, 学士課程, 工学部
  • 化学Ⅰ, 2024年, 学士課程, 全学教育
  • 物理化学演習, 2024年, 学士課程, 工学部
■ Affiliated academic society
  • 日本鉄鋼協会
  • 表面技術協会
  • JAPAN SOCIETY OF CORROSION ENGINEERING
  • 電気化学会
  • The Electrochemical Society
  • The International Society of Electrochemistry
■ Research Themes
  • Study of atmospheric corrosion of steel by hydrogen mapping and surface water analysis
    Grants-in-Aid for Scientific Research
    01 Apr. 2022 - 31 Mar. 2026
    宮本 浩一郎; 伏見 公志; 吉信 達夫
    我々の生活を支える鉄鋼製品は、大気暴露によって表面水薄膜が成長し、飛散物が付着することで大気腐食の危険にさらされる。大気腐食により鋼材中に水素が侵入すると、水素脆化により材料強度が急速に低下する。本研究は、鋼材に侵入する水素の振る舞い、および鋼材表面の水薄膜のダイナミクスを明らかにすることが目的である。
    本年度の成果は以下の通りである。（１）独自に構築した大気下光電子収量測定系によって、鋼材表面に水膜が形成された湿潤状態から、乾燥によって水膜が消失し、塩の析出や腐食進行に至る過程をその場観察することに成功した。薄膜状の水膜、さらに水膜の消失に至る過程を大気下光電子収量法によって測定した初めての成果である。水膜は蒸発や腐食によって成分が大きく変動していると予想されるが、測定データが水膜の性質をどの程度反映しているか解析を進める予定である。（２）電気化学的に鋼材への水素チャージを行い、直ちに大気下光電子収量法による観察を実施する実験系を構築した。（３）鋼材への水素チャージによる仕事関数の変化を示した。さらに段階的な水素チャージによる仕事関数の変化や、チャージ完了後には経時的な仕事関数の回復を観測することにも成功した。大気下光電子収量法によって鋼中の水素が検出可能であることを示唆する初めての成果を得た。この手法は、従来行われてきたケルビンプローブ法による解析より簡便であり、さらに空間分解測定を可能とするポテンシャルも有する。次年度には本手法による測定をさらに進展させる。
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tohoku University, 23K23094
  • Study of atmospheric corrosion of steel by hydrogen mapping and surface water analysis
    Grants-in-Aid for Scientific Research
    01 Apr. 2022 - 31 Mar. 2026
    宮本 浩一郎; 伏見 公志; 吉信 達夫
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tohoku University, 22H01826
  • Development of electrochemical hydrogen absorption-permeation measurement for in-situ determination of trapped hydrogen and analysis of hydrogen embrittlement
    Grants-in-Aid for Scientific Research
    01 Apr. 2022 - 31 Mar. 2025
    伏見 公志; 坂入 正敏; 宮本 浩一郎
    省エネルギー材料として需要の高まる高強度鋼は機械的特性に優れるが、その水素脆化感受性が普通鋼に比べ高い。水素脆化リスクを低減させるため、その前駆過程である水素侵入現象について従来以上の精密な解析が要求されている。水素脆化を誘導する捕捉水素の役割を明らかにするため、本研究では電気化学的水素透過現象における侵入水素、非侵入水素、透過・捕捉水素を高精度にその場解析可能にする新規評価法を開発し、各種鋼材の水素侵入・捕捉量について定量を実現する。
    昨年度、従来の電気化学的水素透過試験法であるDevanathan-Stachurskiセルにチャンネルフロー二重電極法を組み合わせた新しい電気化学測定装置を作製し、電気化学的水素透過測定における試料の水素侵入面および水素引出面、侵入室内の水素検出電極より得られる各電流値より、水素物質収支を解析するその場評価法を開発した。
    本年度、弱酸性硫酸ナトリウム水溶液中、炭素鋼試料のカソード分極により侵入した試料内水素量の試料厚さおよび硬さに対する依存性を明らかにし、侵入面水素量および捕捉水素量を求めた。この侵入面水素量および捕捉水素量は試料硬さ、すなわちトラップ濃度に依存することを確認した。また、本電気化学測定装置をオンラインICP-OESに接続し、侵入室内の水素検出電極における鉄種の干渉の影響を除去できる改良を進めた。これにより
    （鉄が自己溶解する）強酸性水溶液中においても、非侵入水素量を正しく見積もることができるようになった。硫酸水溶液中に浸漬するだけで鉄板には相当量の水素が侵入することがわかった。
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23K23090
  • Development of electrochemical hydrogen permeation measurement for in-situ determination of trapped hydrogen and analysis of hydrogen embrittlement
    Grants-in-Aid for Scientific Research
    01 Apr. 2022 - 31 Mar. 2025
    伏見 公志; 坂入 正敏; 宮本 浩一郎
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 22H01822
  • Real time imaging of thin water layer formation using polarization camera
    Grants-in-Aid for Scientific Research
    09 Jul. 2021 - 31 Mar. 2023
    伏見 公志
    ４角度偏光子を搭載した偏光カメラを検出器とするPSAR型エリプソメーターを作製した。試料は各種鏡面金属であり、温度湿度制御した光学窓付き試料室内に設置した。単色光源としてレーザーを用いた。ポーララーザー（グランテーラープリズム）にて直線偏光とした単色光を試料表面に照射し、表面膜により楕円化した反射偏光の偏光状態（偏光度Ψおよび位相差Δ）を観察できるように設計した。画像データとして得た偏光状態を行列式（L_out = R(-a)AR(a)SR(-p)PR(p)L_in）に代入し、試料表面の水膜厚さ分布像を高速で、すなわち環境条件変化とほぼ同時に取得することを目的とした。なお、L_inおよびL_outは入射および検出した光のストークスベクトル、R, P, A, Sはそれぞれ回転子、偏光子、検光子および試料のミュラー行列、pとaは偏光子と検光子の回転角度である。カラー偏光カメラにおいてa＝0, 45, 90, 135°が設定されていることから、機械的な回転光学素子を使わないで、反射偏光のΨとΔを試料表面（素地、薄膜、環境）の光学定数と薄膜の厚さの関数として求めることができるようにした。従来型のイメージングエリプソメトリーは単色光源であったために、ΨとΔの関係から膜厚を求める解析の際に不都合があったが、本研究では３波長（445、532、633 nm）の同時使用により、膜厚の解析の精度を大幅に向上させた。


    本年度は上述を実現するためのリアルタイムイメージングエリプソメーターの開発とSiO2薄膜試料を用いた校正を重点的に実施した。
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Hokkaido University, 21K18797
  • Preparation and photo-functional properties of lanthanide coordination nanoparticles
    Grants-in-Aid for Scientific Research
    01 Apr. 2018 - 31 Mar. 2021
    HASEGAWA Yasuchika
    In this study, preparations and three-dimensional structural control of luminescent lanthanide coordination nanoparticles have been demonstrated for creation of new molecular materials. Mono-nuclear lanthanide complexes were attached using surface-modified linker ligands on the nanoparticles. Eu(III) complexes fixed on the CaS and SiO2 nanoparrticles show bright red-luminescence. Lanthanide coordination polymers were also fixed on the nanoparticles. The three-dimensional structural control of luminescent lanthanide coordination polymers successfully promoted increase of their emission quantum yields.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 18H02041
  • Passivity Improvement by Made-to-order Scanning Photo-electrochemical Surface Treatment with Ultra Violet-light Beam Irradiation
    Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    01 Apr. 2015 - 31 Mar. 2017
    Fushimi Koji
    Scanning photo-electrochemical apparatus was developed for a new surface treatment. In sulfuric acid, UV-light beam was irradiated on polycrystalline titanium and photo-electrochemical electric charge; photo-electrochemical current integrated by irradiation time was controlled. In-situ ellipso-microscopy and micro Raman spectroscopy revealed that local UV-light irradiation induced dehydration of hydroxide film and then crystallization of amorphous oxide to anatase. Photo-electrochemical polarization with feedback controlling of UV-light irradiation successfully served more homogeneous surface than simple polarization.
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 15K14136
  • Development of in-situ Electrochemical Imaging Plate for Interfacial Reaction and Its Application to Estimation of Residual Lifetime of Metallic Materials
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2013 - 31 Mar. 2016
    Fushimi Koji; HOMMA Takayuki; SAITO Mikiko; LEE Jun-Seob; TAKABATAKE Yu; YANAGISAWA Kei; JIN Misako; YAMAMOTO Yudai
    A 16x16ch Au multielectrode array with a diameter of 10 um and an inter-electrode distance of 100 um was fabricated. Electrochemical measurements using a made-to-order 64 ch multichannel potentiostat revealed that all microelectrodes operated as an individual microelectrode, although their properties varied widely. Polarization of 8x8ch microelectrodes in the array showed an interference of diffusion layer formed on the microelectrodes. The interference was also successfully simulated with a FEM numerical modeling of three-dimensional diffusion problem. The degree of interference during the dynamic polarization of the array could be normalized by the geometry of microelectrode diameter and inter-electrode distance.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 25289235
  • Ultra-high speed in-situ ellipso-microscopic observation of heterogeneous surface change of high-corrosion resistant material
    Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    01 Apr. 2013 - 31 Mar. 2015
    FUSHIMI Koji
    In order to identify the initiation site of local corrosion, a visualization method of passive film with an excellent time resolution was developed. A heterogeneous formation of passive film on titanium during potentiodynamic anodic polarization in sulfuric acid, depending on substrate crystallographic orientation, and an initiation process of local breakdown of passive film in the acid containing with bromide ions were successfully observed by using the developed method. Furthermore, an ultra-violet light irradiation during the anodic polarization resulted the thinning of anodic oxide film and heterogeneous degradation of the film. In the initial period, however, the irradiation led to increase in charge transfer resistance through the film and to improve the corrosion resistance.
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 25630288
  • Enhanced Faraday effect of magneto-semiconductor nanoparticles with inner and out specific interactions
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2011 - 31 Mar. 2015
    HASEGAWA Yasuchika; FUSHIMI Koji
    EuS nanocrystals containing paramagnetic Mn(II), Co(II), or Fe(II) ions have been prepared as advanced semiconductor materials with effective optical rotation under a magnetic field, Faraday rotation. Enhanced Faraday rotations of the EuS:M nanocrystals were observed around 550 nm, and their enhanced spin polarization was estimated using electron paramagnetic resonance (EPR) measurements.
    Thin films composed of EuS nano particle aggregates on a glass electrode exhibited large magneto optical efficiency and a wide energy gap. The Verdet constant of the thin film was approximately 10 times larger than that of previously reported EuS nanoparticles. Remarkable magneto-optical properties of EuS nanocrystals linked with gold (EuS-Au nanosystem) have been demonstrated. The Faraday rotation angle of the EuS-Au nanosystem is dependent on the Au particle size and interparticle distance between EuS and Au nanocrystals. Enhancement of the Faraday rotation of EuS-Au nanosystems was observed.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23350057
  • Real-time lmaging for Initiation of Localized Interfacial Reaction
    Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    2011 - 2012
    FUSHIMI Koji
    Conventionally, mechanism and kinetics of localized interfacial reaction such as local corrosion have not been so cleared because of a lack of methods to investigate an initiation process of the reaction. A state-of-art micro-electrochemical method, which enables to investigate real-time changes in surface morphology as well as products due to localized electrochemical interfacial reaction, is developed and tentatively apPlied to analyze the initiation of local corrosion in this study. An ellipso- microscope, that is combination of null-type ellipsometer and CCD camera micro- imaging, is applied to titanium surface anodized in sulfulic acid and successfully revealed an anisotropic growth of oxide film depending on the substrate and localized degradation of the film in bromide ion-containing solution. Furthermore, a micro- capillary cell technique with 50 pm diameter sample combined with a long-distance optical microscope was developed and apPlied to potentio-dynamic and - static polarizations and electrochemical impedance spectroscopy of iron in sulfuric acid. It revealed that the passivation of the surface and stability of the passive film were strongly depended on crystallographic orientation of the substrate. Combinations of microelectrochemistry and optical microscopy might take a new turn of the research for the initiation of localized interfacial reaction caused by non-uniformity in the scale of surface microstructures.
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 23656440
  • Development of scanning electrochemical nano-scope and analyses of initiation mechanism and kinetics of localized interfacial reaction
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    2009 - 2011
    FUSHIMI Koji; KONNO Hidetaka; HASEGAWA Yasuchika
    New micro-electrochemical techniques developed were applied to investigate the mechanism and kinetics of heterogeneous reaction of the interface between practical materials and environment. Though a probe nano-electrode was successfully developed by using LIGA, the development of a scanning electrochemical nano-scope could not be completed because of the difficulty of probe alignment. However, the application of a coaxial double microelectrode to SECM probe was successfully attained the improvement of sensitivity and lateral resolution of SECM image. Application of this SECM and amicro-electrochemical cell technique to in situ observation of polycrystalline iron surface corroding in acidic sulphate media revealed that iron corroded heterogeneously depending on crystallographic orientation which affected the hydrogen evolution reactivity. The stability of passive state on iron was also strongly dependent on the substrate orientation.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 21360350
  • Plasma electrolytic oxidation of light metals : elucidation of the process and surface functionalization
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    2007 - 2010
    HABAZAKI Hiroki; FUSHIMI Koji; AOKI Yoshitaka
    Plasma electrolytic oxidation (PEO) is an attractive process to form ceramics coatings on light metals, including magnesium, aluminum and titanium, in aqueous electrolytes at ambient temperature. The present study discloses the excellent healing properties of discharge channels in alkaline silicate electrolyte. Further, novel two-step PEO process is developed to form wear-resistant and highly adherent ceramics coating on β-Ti alloy with high mechanical strength and cold workability.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 19206077
  • グロー放電発光分光法による耐食表面の高分解能解析法の確立
    科学研究費助成事業 萌芽研究
    2007 - 2008
    幅崎 浩樹; 伏見 公志
    グロー放電発光分光法(GDOES)がナノ薄膜の迅速分析法として有効であることを示し, 高分解能デプスプロファイルを得るための手法を確立する研究を推進した。まず, 耐海水ステンレス鋼であるSUS312L鋼を用いて, 異なる粒径のアルミナ研磨液を用いて試料を鏡面研磨した。その表面粗さを原子間力顕微鏡(AFM)を用いて計測し, GDOES分析における深さ分解能との相関関係を調べた。研磨条件によりステンレス鋼上に生成する大気酸化皮膜の厚さや組成が変化する可能性があるので, 深さ分解能の評価としてその皮膜直下に存在する銅濃縮層を指標として用いた。GDOESプロファイル上の界面濃縮層の銅のピークの半値幅は表面粗さの対数に対して直線的に変化し, 表面粗さの分解能の影響がきわめて大きいことを明らかにした。同じ鏡面研磨でも表面粗さをできるだけ低減することがナノ薄膜の分析において, 高い深さ分解能を得る上で重要であることを示した。
    また, 従来のX線光電子分光法やオージェ電子分光法などの表面分析法では, 感度が低く, 塩化物イオン含有水溶液中で生成した不動態皮膜中の塩化物イオンをGDOESを用いることで検出できた。塩化物イオンは不動態皮膜中の鉄リッチな皮膜外層にのみ存在しており, クロムリッチな皮膜内層には達していないことを示すことができた。
    以上のように, ステンレス鋼の不動態皮膜や大気酸化皮膜のような厚さ2-3nm程度の表面酸化皮膜でも, 十分に表面を平滑にした試料を用いることで, 高分解能, 高感度で分析できる手法を確立できた。
    日本学術振興会, 萌芽研究, 北海道大学, 19656184
  • Development of carbon hybrids for electric power storage
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    2006 - 2008
    KONNO Hidetaka; AZUMI Kazuhisa; USHIMI Kouji
    高容量・高効率な電気エネルギー貯蔵用カーボンハイブリッドを,環境負荷がなるべく少ない方法(原料・装置などが低コスト, 廃棄物の利用, プロセスが単純あるいは簡易で特殊な装置を必要としない)で合成することを目的とした。リチウムイオン二次電池およびリチウムハイブリッドキャパシターに利用可能なケイ素/炭素/酸素からなる材料および電気化学キャパシターに利用可能な高い電気容量を持つホウ素/炭素/窒素からなる材料を創製することができた。
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 18350102
  • 低コスト炭素化物被覆処理
    2008
    Competitive research funding
  • Development of Surface Finishing Method of Magnesium Alloys for Expansion in Their Application
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    2006 - 2007
    AZUMI Kazuhisa; UEDA Mikito; FUSHIMI Koji
    Magnesium alloy has superior properties such as very light weight and high strength, and natural resource of magnesium is abound. Despite of these excellent nature, very low corrosion resistance hinders them from wide usage in practical applications. This study has aimed to find out the surface finishing method to provide enough corrosion resistivity to magnesium alloys. We developed chemical conversion technique using sodium stannate bath and potentiostatic anodic polarization method. In this technique anodic polarization of magnesium alloy during immersion in the chemical conversion bath causes dissolution of magnesium surface continuously and uniformly, and thus supplies magnesium ions enough to form dense and uniform conversion film. Form optimization of process condition, AD91D alloy was immersed in the bath with various bath composition, temperature, anodic voltage, and immersion time, and surface observation using optical microscope and scanning electron microscope, and corrosion test were applied for evaluation of the coating film. As a result, following optimized condition was obtained; bath temperature 80℃, anodic potential-1.1 V (Ag/AgCl), NaOH concentration 0.125 mol dm^<-3>. From SEM observation of the conversion film deposited in the optimized condition, the film was composed of small particles in μm scale in closely contact to each other, and the gap between these particles is also filled with smaller particles. Such structure enables low density of structural defects in the film and thus high corrosion resistivity. Forced dissolution process of magnesium alloy also suppresses the non-uniform dissolution of the surface depending on composition such as Mg-rich α phase and Al-rich β phases and thus non-uniform deposition on these different phases. This technique is, therefore, expected to be applicable to the coating treatment of magnesium alloy with various shape.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 18560686
  • Structural control and self-organization of the functional oxide films formed on titanium
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    2004 - 2006
    HABAZAKI Hiroki; FUSHIMI Koji; KONNO Hidetaka
    1.Formation of self-organized porous anodic oxide
    We have successfully developed self-organized porous anodic oxide films on Ti-Si alloys in hot glycerol solution containing dibasic phosphate. The key issue for the formation of the porous films is suppression of the crystallization of anodic oxide, which induces gas evolution during anodic film growth. The similar porous films are also developed on niobium and aluminum substrates. The cell size of the porous films on aluminum is dependent upon the formation voltage, similar to those formed in acid aqueous solutions.
    2.Formation of barrier-type anodic oxide with excellent dielectric properties
    Incorporation of foreign species from substrate suppresses effectively the development of crystalline anodic oxide on titanium. By increasing alloying element content, the structure of the air-formed film present before anodizing is modified, such that growth of amorphous oxide continues to higher formation voltages. The compositional dependence of the dielectric properties of anodic oxides formed on a range of titanium alloys has been examined systematically.
    3.Hard coating of titanium alloys by spark anodizing
    Spark anodizing of titanium, Ti-6Al-4V and Ti-15V-3Al-3Cr-3Sn has been performed in alkarine electrolyte containing aluminate and phosphate. Highly crystalline Al2TiO5-based oxide coatings,〜20μm thick, have been developed by dc-biased ac anodizing to high voltages. Regardless of the materials used, the coatings with hardnes of 〜6GPa have been obtained. The coatings have porosity, associated with discharge channel. From optical measurements during spark anodizing, the temperature at the discharge region has been estimated to be 4500〜5000℃. Such high temperature allows us to develop the highly crystalline coatings with high concentration of electrolyte species even in an aqueous solution at ambient temperature.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 16360353
  • メガHz帯域交流インピーダンスの走査電気化学顕微鏡への適用
    科学研究費助成事業 若手研究(B)
    2004 - 2005
    伏見 公志
    前年度の研究実績(プローブを超音波振動させることにより、試料表面に近接した際のプローブ-試料表面間のシアフォースを検知できるようにし、試料表面とプローブの間の距離制御に応用した)によりその機能が向上した走査電気化学顕微鏡(SECM)に、パルス電源および電流検出回路を組み入れた。この改良は、試料電極とプローブ電極間にメガHz帯域の電圧波形を入力し、流れる過渡電流の計測を目的としている。これにより、オンタイムで約30MHzまでの矩形波パルスに伴う電流検出(電流検出時間分解能:10ns、感度10μA)が可能となった。
    ヘキサシアノ鉄(II)酸カリウム水溶液中、直径10μmの白金微小ディスク電極とモデル試料(エポキシ樹脂に埋め込んだ白金ディスク電極)間に振幅1〜5V、幅100ns、デューディ比10〜1000の矩形波パルスを印加し、パルスに伴う過渡電流を解析した結果、過渡電流の初期に流れる電流は、プローブと試料それぞれの電極表面上に形成する電気二重層の充電に消費され、その時定数は両電極間の液抵抗と二重層容量の積で表されることを確認した。また、過渡電流後半の電流は、充電完了後のファラディック電流に対応し、プローブ-試料電極間距離に応じて流れることを観察した。すなわち、充電電流とファラディック電流はプローブ直下の試料表面上で最も迅速に流れ始め、プローブ直下以外の周辺部には遅れて流れる。また、両電流はモデル試料表面の電気特性に依存し、導電体(白金)と絶縁体(エポキシ樹脂)の区別を可能とするものである。しかし、これらの電流を実際にSECMの結像信号として用いたときの電流像の面分解能は、従来法(直流の定常ファラディック電流)による面分解能に著しく劣るものであった。この理由は、プローブ-試料電極間の時定数が面分解能に影響するためであり、面分解能の向上にはより短い幅でオーバーシュートのないきれいな形状のパルスを入力すること、出力される電流を高感度に検出することが要求された。本装置の仕様を大きく上回る計測技術の導入により改善される可能性はあるが、本研究の範囲内では実施不可能であった。
    なお、以上の研究成果は第56回国際電気化学会(Busan,Sep.2006)にで報告した。
    日本学術振興会, 若手研究(B), 北海道大学, 16760581
  • マイクロインデンテーション法による不働態表面のメカノエレクトロケミストリ
    2003
    Competitive research funding
  • Mechano-electrochemistry of passive surface by micro-indentation method
    2003
    Competitive research funding
  • Nano-mechano-electrochemistry of Passive Metal Surfaces
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    2001 - 2002
    SEO Masahiro; FUSHIMI Koji
    Nano-indentation and nao-scratching tests in solution were performed for in-situ evaluation of the mechano-electrochemical properties of passive single crystal iron and polycrystalline titanium surfaces electrochemically controlled in pH 8.4 borate solution. The hardness and friction coefficient of passive metal surfaces in solution could be determined from the load-depth curves measured with nano-indentation tests and from the lateral force curves measured with nano-scratching test, respectively. The hardness of the passive iron (110) surface was larger than that of the passive iron (100) surface, while the friction coefficient of the (110) surface was less than that of the (100) surface. The chromate treatment increased the hardness of both iron (110) and (100) surfaces.
    The hardness and friction coefficient of the titanium surface obtained with nano-indentation and nano-scratching under the electrochemical control at 5 V were significantly larger than those of the titanium surface obtained with nano-indentation and nano-scratching in air after anodic oxidation at the same condition. The large values of hardness and friction coefficient in solution were attributed to high repassivation rate at the ruptured sites of anodic oxide film under the electrochemical control at 5 V.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 13450288
  • 局部的電気化学反応の解析と応用
    2001
    Competitive research funding
  • Analysis and application of localized electrochemical reactions
    2001
    Competitive research funding
  • 微小電極の新規作製法の開発とその工学的応用
    2000
    Competitive research funding
  • Fubrication and application of microelectrode technique
    2000
    Competitive research funding
  • COMBINATION OF SCANNING ELECTROCHEMICAL MICROSCOPY AND LOCAL ELECTROCHEMICAL IMPEDANCE METHOD
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    1998 - 1999
    SEO Masahiro; FUSHIMI Koji; AZUMI Kazuhisa
    The combinational use of scanning electrochemical microscopy (SECM) and other micro-electrochemical techniques, such as local electrochemical impedance method (LEIM), scanning droplet cell (SDC) and liquid-phase ion gun, was attempted to evaluate the heterogeneity of electrochemical reaction at the metal and solution interface in a scale of several μm to several ten μm. Furthermore, the performance of SECM was improved to obtain the more precise probe current images. The following results were obtained.
    1. Micro-disk platinum electrode for SECM was combined with micro-platinum black electrodes for LEIM. A platinum foil embedded into epoxy resin was used as a model specimen electrode. Both SECM and LEIM images could distinguish clearly between the platinum foil and epoxy resin although the lateral resolution of LEIM was several ten times as much as that of SECM.
    2. SDC, in which a droplet of electrolyte solution can be scanned over the specimen electrode surface, was combined with SECM. The voltammetry and impedance spectra of a polycrystalline gold electrode measured with SDC have revealed that all grains have a (111) orientation but different azimuth angles. SDC was also applied to form locally anodic oxide films on titanium electrode surface. The local formation of anodic oxide film could be evaluated by SECM.
    3. A micro silver electrode covered with silver chloride was employed as a probe electrode of SECM. A small mount of chloride ions could be generated locally with a cathodic polarization of the microelectrode, which was named "liquid-phase ion gun". The use of liquid-phase ion gun succeeded in inducing the local breakdown of passive film on iron electrode. The critical amount of chloride ions needed for initiating the local breakdown depended on the film formation conditions, the electric field in film, and pH of solution.
    4. The probe current image of titanium electrode in sulfuric acid solution was measured by detecting oxygen which evolved from the electrode in parallel with film formation during anodic polarization. This probe current image coincided with the probe current image obtained with the conventional SECM measurement in which the redox system of ferrocyanide ions was employed as a mediator. Comparison between the probe current images and optical micrograph has indicated that the heterogeneity of oxygen evolution depends on the crystallographic orientation of the substrate titanium and the oxygen evolution takes place preferentially on the thinner passive film or the film with the higher donor density.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 10555236
  • Corrosion Behavior of Titanium in Deaerated Aqueous Solutions
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    1998 - 1999
    AZUMI Kazuhisa; FUSHIMI Koji; SEO Masahiro
    Titanium is one of the candidates for overpacking material of glass log containing high level radioactive waste produced in power plants. The overpacking material has to protect its contents over 1000 years from environment such as underground water containing chemical composition dissolved from bentonite clay and high temperature up to 100 degree due to heat production of nuclear fission reaction. In this study Ti specimens were immersed in deaerated water in contact with bentonite powder, borate buffer solution, or carbonate solution, and obtained following results. (1) Oxide layer grows on Ti mechanically polished even in deaerated aqueous solution. (2) Electric barrier property degraded during long term immersion. (3) Immersion potential became unstable after long term immersion. (4) Dissolution traces of general corrosion were observed after 20 weeks immersion. (5) Initiation of localized corrosion was observed in aqueous solution in contact with bentonite powder. (6) Corrosion traces and degradation of the film was more obvious at 80 degree than 25 degree. From impedance results, the corrosion rate and degradation of the oxide film were mostly affected by the presence of sulfate ion. From impedance results and AFM observation the anodic oxide film formed on Ti in the solutions containing sulfate ion such as bentonite contact solution has porous structure and electric defects at high density, resulting in more susceptible to the degradation and corrosion. In the present study crevices with a few tenth nm in depth were observed on Ti after 20 weeks immersion. Therefore, it is important to evaluate the possibility that the crevice grows to more serious localized corrosion.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), HOKKAIDO UNIVERSITY, 10650683
  • MECHANO-ELECTROCHEMISTRY OF MICRO-SURFACE AREA OF MATERIALS
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    1997 - 1999
    SEO Masahiro; FUSHIMI Koji; AZUMI Kazuhisa
    Nanoindentation tests were performed for the single crystal iron (100) surfaces electrochemically controlled in pH 8.4 borate solution to measure the load-depth curves from which the mechanical properties such as hardness and elastic modulus of the iron surfaces were evaluted to obtain the fundamental knowledge for estabilshment of mechano-electrochemistry. The hardness of the iron surfaces was fluctuated depending on the position of nano-surface area. The average value of hardness, however, took a minimum at 0.25 V in the passive potential region. At the potential above 0.25 v, the average hardness increased linearly with increasing the potential, I.e., the thickness of passive film. The hardness of film itself could be separated from that of the substrate iron by using the linear relation between average hardness and film thickness. Moreover, the nanoindentation tests were performed for the single crystal iron (100) and (110) surfaces passivated at 1.0 V in pH 8.4 borate solution to investigate the depedence of hardness on crystal orientation of the surface. However, no significant differences in hardness was observed between single crystal iron (100) and (110) surfaces.
    The hardness of the polycrystalline titanium surfaces subjected to anodic oxidation in various electrolyte solutions was measured as a function of formation potential of anodic oxide film. The hardness increased with increasing the film formation potential up to 8 V. The hardness decreased rapidly above 8 V at which the local breakdown of the film would take place. Moreover, the largest hardness was observed for the titanium surfaces subjected to anodic oxidation in sulfuric acid. The stresses generated in the anodic oxide film on titanium were measured by a laser-beam deflection method to investigate the relation between stress in the film and hardness. The largest compressive stresses were generated in anodic oxide film on titanium in sulfuric acid. Therfore, it is found that there is a good correlation between compressive stress and hardness. The partial release of the compressive stresses were observed at the potential above 8 V at which the local breakdown of anodic oxide film took place. The rapid decrease in hardness at the potential above 8 V was ascribed to the partial release of compressive stress ue to local breakdown of anodic oxide film.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), HOKKAIDO UNIVERSITY, 09305047
  • 液中イオン銃による不働態皮膜の局部破壊に関する研究
    科学研究費助成事業 奨励研究(A)
    1997 - 1998
    伏見 公志
    鉄など金属材料の局部腐食は,最も危険な腐食形態である。しかし,局部腐食の反応機構,特に前駆過程には不明な点が多い。本研究は,溶液環境中で金属表面を覆う不働態皮膜に対して,攻撃性アニオンを打ち込むことのできる"液中イオン銃"を開発し,局部腐食前駆過程の解析に適用した。
    1. 液中イオン銃には,直径180μmの銀線をガラス管に封入し,先端をディスク状に研磨した後,塩化銀を被覆した微小電極を用いた。液中イオン銃の電極チップからの塩化物イオンの発生は,カソード分極により行った。塩化物イオンの発生効率は,ほぼ100%であり,カソード電気量に比例することを確認した。また,塩化物イオンの発生後には,液中イオン銃の電極チップは,不働態皮膜から溶出する鉄(III)イオン等の検出にも有用であることを確認した。
    2. 被測定物である金属試料の電極電位を制御しながら,液中イオン銃を作動させるために,当研究室で開発した走査電気化学顕微鏡を応用した。すなわち,コンピュータにより制御された走査ステージに液中イオン銃を取り付け試料電極との距離を制御し,バイポテンショスタットを用いて試料電極および液中イオン銃の電位の制御と電流の検出を行った。
    3. 鏡面研磨した鉄試料表面に,pH6.5のホウ酸塩水溶液中,一定電位E_aでアノード分極することにより不働態皮膜を作成した。引き続き,試料電位をE_aに保持したまま,試料電極表面の上方75μmに配置した液中イオン銃を塩化物イオンを生成する電位-0.1V_に電位規制した結果,数十秒の誘導時間の後,鉄試料に流れるアノード電流が急激に増加し,イオン銃直下の不働態皮膜は局部的に破壊した。一方,アノード電流の増加する間,イオン銃に流れるカソード電流は塩化物イオンの生成電流よりも,異常に増加した。この異常電流は,鉄(III)イオンの還元反応に起因するものであり,皮膜が局部的に破壊される前に塩化物イオンにより,不働態皮膜から鉄(III)イオンが溶出するものと示唆された。皮膜破壊後,試料アノード電流は定常値となり,腐食サイトの窪みは深くなった。一方,イオン銃のカソード電流は,ほとんど零になった。すなわち,皮膜破壊部から鉄(II)イオンが溶出する反応機構で局部腐食が進展することを確認した。これらの局部腐食発生過程は,皮膜作成電位E_aにより異なった。
    日本学術振興会, 奨励研究(A), 北海道大学, 09750781
  • Construction of a Scanning Electrochemical Microscope for Evaluation of the Heterogeneity of Passive Films
    Grants-in-Aid for Scientific Research
    1996 - 1997
    SEO Masahiro; FUJIMOTO Eiji; FUSHIMI Koji; TAKAHASHI Hideaki
    A scanning electrochemical microscope (SECM) was successfully constructed to evaluate the heterogeneity of passive films. A cross section of Pt wire with a diameter of 10mum sealed into glass tube was used as a scanning probe electrode. A commercial type of potentiostat was improved to a bipotentiostat which is capable of controlling independently the potentials of probe and specimen electrodes. The constructed SECM has a lateral resolution of 20mum, wich is two times as much as a diameter of probe electrode.
    Two iron plates embedded in epoxy resin were anodically polarized at different potentials in pH8.4 borate solution to form passive films with different thickness. Afterward, in pH8.4 borate solution containing Fe (CN) _6^<4->, the probe electrode was polarized at the potentioal at which Fe (CN) _6^<4-> can be oxidized to Fe (CN) _6^<3->, whereas the two iron plates were polarized at the potetial at which Fe (CN) _6^<3-> can be reduced to Fe (CN) _6^<4->. The difference in thickness between passive films on two iron plates could be distinguished from the probe current image. The heterogeneity of passive film formed on polycrystalline iron electrode with distinct grains was also examined in the same manner. The probe current image depended on the grain orientation and the probe current increased in the order of grain orientation, {100}, {111}, and {110}. This difference in probe current results from the difference in thickness of passive films.
    An electropolished titanium specimen was anodically oxidized in pH 8.4 borate solution to form the passive film. The heterogeneity of the passive film was evaluated using the SECM.It is found from the probe current image that the heterogeneity of the passive film increases with increasing anodic potential for film formation above 4 V_. This heterogeneity corresponds to the shape of each substrate grain, suggesting that the passive film on each substrate grain differs in thickness and defective structure.
    A scanning photoelectrochemical microscope (SPECM) is being developed by attaching an optical fiber to the probe electrode of SECM.SPECM would be useful to evaluate the difference in defective structures of the passive films.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), HOKKAIDO UNIVERSITY, 08555166
  • マイクロインピーダンス法による鉄および炭素鋼の局部腐食前駆過程の評価
    科学研究費助成事業 奨励研究(A)
    1996 - 1996
    伏見 公志
    1.鉄および炭素鋼などの金属表面の電極特性を微小領域毎に評価する走査プローブ顕微鏡の構築を試みた。プローブは、試料表面近傍に配置した2本の微小電極であり、微小電極間に交流正弦電圧を印加し、同期する電流応答(マイクロインピーダンス)を計測する設計とした。微小電極には、先端径を100μm程度に絞ったガラス管内に0.5mmφの白金線を挿入したものを作製した。プローブ電極は、位置決め分解能0.1μmのXY軸およびZ軸ステージをオートマイクロエンコーダにより走査した。また、試料表面観察用にCRT上で250倍の光学顕微鏡を取り付けた。
    2.プローブと試料の電極間距離は、再現性良く制御する必要があった。まず、光学顕微鏡による制御法を検討したが、プローブが破壊するなどして、操作性および再現性に優れなかった。そこで、プローブ電極に別途直径10μmの微小ディスク電極を取り付け、酸化還元体を含む溶液中において定電位分極した際の限界電流を指標とする電極間距離制御法を導入した。微小電極上の拡散層の厚さ以内にプローブが試料に接近すると、限界電流は再現性良く試料の伝導性により変化した(絶縁体試料の場合、減少し、導電体試料場合には増加した)。この方法により、定量的に電極間距離の基準点を定めることが可能となった。
    3.原理上、マイクロインピーダンスは2つの微小電極間に存在する溶液の抵抗と容量に依存し、面分解能はプローブをより微小とすることにより向上することが予想された。本研究では、研究室に既存していたポテンショスタット、ファンクションジェネレーターおよびロックインアンプにより、先端径100μmの自作電極を用いて、濃度の異なる水酸化ナトリウム水溶液のマイクロインピーダンスを試験測定したが、重畳印加電圧を数100mVとしても、溶液濃度に依存するマイクロインピーダンスの有意差を測定することができなかった。原因としては、微小電極自身の内部インピーダンスが大きいためにノイズレベルが高いこと、およびポテンショスタットの周波数応答性が悪いことが考えられた。微小電極の改善とともにポテンショスタットの改良あるいは新規導入を検討する必要があることが明らかとなった。
    日本学術振興会, 奨励研究(A), 北海道大学, 08750826
  • 走査型電気化学顕微鏡による界面構造の解析と創製
    1996
    Competitive research funding
  • Analysis and fabrication of interface structure by scanning electrochemical microscopy
    1996
    Competitive research funding
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