Development of electroactive materials through the analysis of electronic phase diagrams of epitaxial transition-metal oxides

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03881
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Device related chemistry
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: OHTOMO Akira 東京工業大学, 物質理工学院, 教授 (10344722)
• Co-Investigator(Renkei-kenkyūsha): MATSUMOTO Yuji 東北大学, 工学研究科, 教授 (60302981) ; KUMIGASHIRA Hiroshi 高エネルギー加速器研究機構, 物質構造科学研究所, 教授 (00345092) ; YOSHIMATSU Kohei 東京工業大学, 物質理工学院, 助教 (30711030)
• Research Collaborator: MASHIKO Hisanori ; NAKAMURA Kentaro ; KUROKAWA Hikaru ; SOMA Takuto
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 薄膜・表面 / 超伝導 / 光触媒 / 遷移金属酸化物 / エピタキシャル成長 / 電気化学セル / 金属－絶縁体転移

Outline of Final Research Achievements

The transition-metal oxides, such as titania and hematite, are conventional materials utilized in various electrochemical cells because of their non-toxic, earth-abundant, and stable nature. This research aims at adding new electrochemical functionalities to them by combining the power of epitaxial growth techniques and newly developed phase-diagram analysis method. We implemented a compact electrochemical cell to test a number of thin-film samples. Representative achievements are summarized as follows: (i) band-gap narrowing in ferrite based films and orientation control of hematite films resulted in substantial improvement of visible-light driven photoelectrochemical water oxidations; (ii) complete and reversible superconductor-insulator transitions in lithium titanate films were achieved by Li-ion electrochemical reactions; (iii) superconductivity in higher titanium oxides films was discovered. Our approach is a powerful way to find new functionalities for sustainable society.

Free Research Field

固体化学