Investigation into mechanism of functional expression in magnetic materials with transition-metal substitution

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05135
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26040:Structural materials and functional materials-related
• Research Institution: Kagoshima University
• Principal Investigator: fujii shinpei 鹿児島大学, 理工学域理学系, 教授 (90189994)
• Co-Investigator(Kenkyū-buntansha): 三井 好古 鹿児島大学, 理工学域理学系, 准教授 (90649782)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 第一原理計算 / 磁性材料

Outline of Final Research Achievements

The theoretical group have obtained the following achievements: the structural transition barriers (STBs) of Fe- and Cu-substitution systems are lower than that of MnCoGe; there is not an outstanding difference in the value of STB between two substituted systems; the Fe-substitution system on Co site is expected to be the largest magnetocaloric effect in terms of the change of volume expansion and magnetization in the structural transition; Fe prefers the both-site substitution.
The most important found of the experimental group is as follows: Fe substitutes both the Co and Mn sites even if a substitution for the Co site is intended; the ratio of an occupancy of the two sites is constant irrespective of Fe concentration.

Free Research Field

計算物理

Academic Significance and Societal Importance of the Research Achievements

本研究の対象物質は、高価な希土類元素も有害な物質も含まない強磁性体で、世界的に注目されていた。具体的には、世界的にその機能性発現が注目されている(1)MnCoGe-Fe置換系と、比較物質である非磁性置換系の(2)MnCoGe-Cu置換系に絞り研究を実施した。理論と実験同時アプローチによる研究は少なく、機能性発現の観点からの遷移金属性磁性体研究を世界に発信した。本研究の成功は、機能性材料の研究・開発分野を大きく前進させることに貢献した。