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Uchida Hiroshi

  (内田 寛)

Profile Information

Affiliation
Professor, Faculty of Science and Technology, Department of Materials and Life Sciences, Sophia University
Degree
修士（工学）(Mar, 1997, 上智大学)
博士（工学）(Jan, 2001, 東京工業大学)
Contact information
uchidahsophia.ac.jp
Researcher number
60327880
J-GLOBAL ID
200901055907958881
researchmap Member ID
1000367338

Apr. 2000 - present
Department of Chemistry, Sophia University (Research Associate)
(i) "Material-research for novel ferroelectric thin films applicable to nonvolatile random access memories" (Apr. 2000 -)
(ii) "Development of novel film-deposition techniques using supercritical fluids" (Apr. 2003 -)
[Supervisor: Prof. Isao Okada (Apr. 2000 - Mar. 2003), Prof. Seiichiro Koda (Apr. 2003 -)]

Apr. 1997 - Mar. 1999
Department of Inorganic materials, Tokyo Institute of Technology (Doctorial research)
(i) "Study on Residual Stress Analysis and Effect of the Stress on Dielectric Properties of Ferroelectric Lead Titanate Thin Film"
[Supervisor: Prof. Nobuyasu Mizutani]

Apr. 1995 - Mar. 1997
Department of Applied Chemistry, Sophia University (Master research)
(i) "Study on nitride ceramics of ternary Mg-Si-N system with high thermal conductivity"
[Supervisor: Prof. Akira Kishioka]

(Subject of research)
Fabrication and Evaluation of Ferroelectric Thin Films by Chemical Solution Deposition
Development of lead-free ferroelectirc thin films
Chemical process for synthesis of inorganic materials using supercritical fluids
Hydrothermal synthesis of metal-oxide thin films

Research Interests

 9

Research Areas

 3

Research History

 6
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Education

 3

Papers

 237
  • Weirong Yang, Hiroshi UCHIDA, Taro Kuwano, Hiroki TANIGUCHI, Shintaro Yasui
    Japanese Journal of Applied Physics, Jul 31, 2026  Peer-reviewed
    Abstract Lead-free antiferroelectric (AFE) materials with non-perovskite structures are of increasing interest for environmentally friendly high-power energy storage applications. Titanite CaTiSiO 5 thin films with different thicknesses were fabricated on (111)Pt/(100)Si substrates by pulsed laser deposition. Post-annealing under oxygen partial pressures of 50 Torr or higher reduced the leakage current density, owing to the suppression of oxygen-vacancy-related defects. XRD analysis confirmed the formation of single-phase monoclinic P 2 1 / a titanite films with 011 preferred orientation. The Lotgering factor for the 011 orientation reached approximately 0.8 for films thicker than 280 nm. With increasing thickness, the relative permittivity decreased from approximately 100 to 50, approaching the value reported for bulk titanite. Films thicker than 280 nm exhibited clear double polarization–electric field hysteresis loops, confirming stable antiferroelectric behavior. These results reveal the thickness-dependent evolution of texture growth and electrical properties in titanite CaTiSiO 5 thin films.
  • Hiroshi UCHIDA, Ryohei Okamoto, Takuma Ito, Yukie Yokota, Hiromi SHIMA, Yoshitaka Ehara, Hiroshi Funakubo
    Japanese Journal of Applied Physics, 65(15) 15SP04, Jul 24, 2026  Peer-reviewedLead authorLast authorCorresponding author
    Abstract The compositional dependence of phase-formation behavior in fluorite-type ferroelectric films of the binary HfO 2 – ZrO 2 system was systematically evaluated while considering the size effect associated with film thickness. The crystalline phase of the CSD-derived films (1- x ) HfO 2 - x ZrO 2 films ( x = 0 - 1.00) generally exhibited a transition from the monoclinic fluorite (m-phase) to orthorhombic and / or tetragonal phases (o-/t-phase) with increasing the ZrO 2 content. However, the phase boundary between m-phase and o-/t-phases shifted toward the ZrO 2 -rich region as the film thickness decreased. The composition exhibiting enhanced ferroelectricity also shifted toward the ZrO 2 -rich side, coincident with the phase boundary: the 40 nm-thick films showed the maximum remnant polarization at x = 0.75, which is noticeably different from the commonly reported optimum composition of x = 0.50 (i.e., Hf0.5Zr0.5O 2 ) for ultrathin (~9 nm) films.
  • Tatsuya Masuda, Hiromi SHIMA, Hiroshi UCHIDA, Shintaro Yasui, Hiroki MORIWAKE, Yoshitaka Ehara
    Japanese Journal of Applied Physics, 64 10SP01, Sep 11, 2025  Peer-reviewed
    Abstract This study systematically investigated the role of Ba(OH)2 concentration on the properties of thin films. Films of (001)-oriented barium titanate (BaTiO3) were grown on (100) La-doped SrTiO3 substrates at 200°C by hydrothermal synthesis. X-ray diffraction analysis confirmed the films showed epitaxial and highly (100)-oriented growth with no secondary phases. The as-deposited films exhibited a significant unit cell volume expansion relative to bulk BaTiO3, which is attributed to the incorporation of hydroxyl (OH-) groups inherent in the hydrothermal process. Scanning electron microscopy revealed that a high Ba(OH)2 concentration (2.0 mol dm⁻3) was essential to achieving a uniform film approximately 150 nm thick, lower concentrations resulted in discontinuous growth. The dense film exhibited a clear ferroelectric domain structure and good dielectric properties. These results demonstrate that precise control over precursor concentration is a key factor in fabricating high-quality epitaxial ferroelectric oxide thin films via low-temperature hydrothermal methods.
  • Kohei Noji, Yukie Yokota, Hiromi Shima, Hiroshi Funakubo, Hiroshi Uchida
    Journal of the Ceramic Society of Japan, 133(7) 281-287, Jul 1, 2025  Peer-reviewedCorresponding author
  • Yukie Yokota, Nazuna Itabashi, Mari Kawaguchi, Hiroshi Uchida, Nick Serpone, Satoshi Horikoshi
    Molecules, Apr, 2025  
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Misc.

 60
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Books and Other Publications

 5

Presentations

 107
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Professional Memberships

 5

Research Projects

 21
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Industrial Property Rights

 8
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