Crystal structure and oxygen storage properties on layered manganese oxides

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05092
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Osaka Metropolitan University (2022); Osaka Prefecture University (2020-2021)
• Principal Investigator: Ishibashi Hiroki 大阪公立大学, 大学院理学研究科, 准教授 (70285310)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 結晶構造解析 / 放射光粉末回折 / 層状マンガン酸化物 / 酸素貯蔵材料

Outline of Final Research Achievements

We investigated the oxygen absorption and release properties and the crystal structure of Ti-substituted RMnO3 with a layered structure which is known as the oxygen storage materials. The results show that the Ti-substituted system of HoMnO3 has a composition with excess oxygen and a trigonal structure similar to the oxygen absorption phase of HoMnO3, which shows reversible oxygen absorption and desorption properties. High resolution X-ray powder diffraction data with high-counting statistics obtained by synchrotron radiation source of SPring-8 revealed that the oxygen occupancy in the (Mn/Ti)O plane can change flexibly due to the displacement of Ho atoms during the oxygen absorption and desorption processes.

Free Research Field

構造物性

Academic Significance and Societal Importance of the Research Achievements

本研究により、層状酸化物RMnO3のTi置換体も酸素吸収・放出の挙動を起こすことを新たに見いだした。さらに、高輝度放射光を用いた高分解能粉末回折により、その挙動の動的な変化を原子レベルで捉え、R原子の変位と(Mn/Ti)O面の酸素の占有を柔軟に変化させることが酸素吸収・放出に重要な役割を果たしていることがわかった。これらの新しい知見は、今後の新規な酸素貯蔵材料の開発への指針となることが期待される。