Katayama Tsukasa

Research Institute for Electronic Science　Green Nanotechnology Research CenterAssociate Professor
Last Updated :2025/11/06

■Researcher basic information

Degree

  • Doctor of Science, The University of Tokyo, Mar. 2016

Researchmap personal page

Home Page URL

Researcher number

  • 50784617

ORCID ID

J-Global ID

Research Keyword

  • oxide thin films

Educational Organization

■Career

Career

  • Apr. 2021 - Present
    Hokkaido University, Research Institute for Electronic Science, Associate Professor, Japan
  • Oct. 2021 - Mar. 2024
    JST さきがけ (兼任)
  • Jan. 2019 - Mar. 2021
    The University of Tokyo, Graduate School of Science, Assistant Professor, Japan
  • Jan. 2018 - Dec. 2018
    The University of Tokyo, Graduate School of Science, Assistant Professor, Japan
  • Apr. 2016 - Dec. 2017
    Tokyo Institute of Technology, Laboratory for Materials and Structures, Ph.D. researcher, Japan
  • Apr. 2014 - Mar. 2016
    Japan Society for the Promotion of Science, 特別研究員, Japan

Educational Background

  • Apr. 2013 - Mar. 2016, The University of Tokyo, Graduate School of Science, Department of Chemistry, 博士課程, Japan
  • Apr. 2011 - Mar. 2013, The University of Tokyo, Graduate School of Science, Department of Chemistry, 修士課程, Japan
  • Apr. 2007 - Mar. 2011, The University of Tokyo, Faculty of Science, Department of Chemistry, Japan

■Research activity information

Papers

Research Themes

  • Development of charge and spin functionality via domain engineering
    Grants-in-Aid for Scientific Research
    01 Apr. 2020 - 31 Mar. 2024
    片山 司
    遷移金属酸化物は遷移金属元素の種類と結晶構造の組み合わせにより、光触媒・高温超伝導・巨大磁気抵抗・強誘電などの多種多様な物性を示すため、基礎研究から応用開発まで精力的な新奇物性探索が展開されている。中でも最近注目され始めたのが、ナノドメイン構造制御による機能拡張である。例えば、ドメイン境界を活用することでバンドギャップ以上のエネルギーの光起電力を得ることや、磁気スピン秩序を反強磁性から強磁性に変調すること、さらに二次元超伝導の発現など様々な新奇物性が報告されている。この様なドメイン由来の新奇物性を広く活用する上で、高密度ドメインを酸化物中に形成することが重要となる。しかしながら、これまで酸化物薄膜でのドメイン密度(単位面積当たりのドメイン数)は小さく、マクロ物性への影響は限られていた。2021年度、申請者はマルチフェロイック材料の六方晶希土類酸化物(h-RFeO3)系材料に注目し、研究を進めた。申請者は希土類イオンの大きさを制御することで、h-RFeO3薄膜内にP63cm構造とP-3C構造から成る高密度ドメインを膜内に形成し、この系で初めての室温反強誘電特性の発見に成功した。さらに、膜厚を系統的に変化させることで強誘電―反強誘電相転移を温度変化により引き起こすことに成功した[B. Chen, T. Katayama* et al., J. Mater. Chem. C 10, 5621 (2022).]。またこの反強誘電-強誘電転移温度はc/a値の制御により変化させることができた。さらに申請者はダブルペロブスカイトRBaCo2O5.5を対象に研究を進め、結晶ドメインを導入することで磁化の変調を可能にした[T. Katayama* et al., Chem. Mater. 33, 5675 (2021).]。
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), 20H02614
  • Investigation of single crystalline oxide sheet
    Grants-in-Aid for Scientific Research
    01 Apr. 2018 - 31 Mar. 2020
    Katayama Tsukasa
    I fabricated single-crystalline SrRuO3 and BaTiO3 flexible sheets with a few millimeters lateral size. The SrRuO3 sheet exhibits high crystallinity and conductivity. Meanwhile, ferroelectricity of the BaTiO3 sheet was successfully observed by the polarization hysteresis loop measurements. In addition to the simplicity, this method is low cost as a substrate is reusable. Accordingly, the proposed method could enhance a development of various kinds of large-size functional oxide sheets.
    Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, The University of Tokyo, 18K14122
  • Investigation of multiferroic GaFeO3-type oxide thin films
    Grants-in-Aid for Scientific Research
    26 Aug. 2016 - 31 Mar. 2018
    Katayama Tsukasa
    I investigated chemical substitution effect on magnetic and ferroelectric properties of multiferroic GaFeO3-type oxide thin films. I found that leakage current significantly decreases with Sc doping, resulting in clear ferroelectric hysteresis loops. Furthermore, I found that the magnetic properties are widely controllable via chemical substitution.
    Japan Society for the Promotion of Science, Grant-in-Aid for Research Activity Start-up, 16H06794
  • Design of perpendicularly magnetized multiferroic
    Grants-in-Aid for Scientific Research
    01 Apr. 2015 - 31 Mar. 2018
    ITOH MITSURU, YASUI Shintaro, TANIYAMA Tomoyasu, HAMASAKI Yosuke, MORIWAKE Hiroki, KATAYAMA Tsukasa
    This study was conducted for the purpose of the materials design and structural design of the meultiferroelectric device in order to control of their magnetization by the external electric field. First, thin films of the materials with κ-alumina-type structure were fabricated to investigate ferroelectric and ferrimagnetic properties. Ferroelectricity was confirmed for the all the prepared films. Secondary, ScFeO3 film with YMnO3-type structure, in magnetization is aligned along the perpendicular axis of the film, was fabricated for the fist time. Perpendicular magnetization and ferroelectricity were confirmed at the room temperature. Multiferroic κ-akumina-type this films could be also prepared by the sole-gel and ALD technique.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Tokyo Institute of Technology, 15H02292