Study of hydrogen-induced metal-insulator transition in RNiO3 and its exploration of high concentration phases

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14600
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 29020:Thin film/surface and interfacial physical properties-related
• Research Institution: The University of Tokyo
• Principal Investigator: Ozawa Takahiro 東京大学, 生産技術研究所, 助教 (20910144)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 水素 / ニッケル酸化物 / ペロブスカイト / 金属絶縁体転移

Outline of Final Research Achievements

The relation between hydrogen concentration and electrical resistance in perovskite nickel oxides ReNiO3 was investigated by resonant nuclear reaction analysis combined with in-situ resistance measurement. The samples were epitaxial thin films of SmNiO3, NdNiO3 and LaNiO3. It was found that the perovskite nickel oxides exhibit metal-insulator transition at the hydrogen concentration of x = 0.5. The results indicated that the insulator phase is a universal property of ReNiO3 regardless of Re elements.

Free Research Field

水素化物

Academic Significance and Societal Importance of the Research Achievements

近年, 水素エネルギーの機運の高まりととも水素駆動デバイスや水素ガスセンサーなどの研究開発が熱心に行われている. 特にペロブスカイト型酸化物は様々な場面で注目され, それらへの応用開発には, 酸化物と水素の相互作用の基礎的理解が欠かせない. 本研究では共鳴核反応法を用いた水素濃度測定を用い, ペロブスカイト型ニッケル酸化物の水素と電気伝導特性の関係を詳細に調べた. 水素濃度0.5の絶縁体相の存在を実験的に明らかにした.