Theoretical study of finite-temperature magnetic properties of ferromagnetic metals with uniaxial magnetic anisotropy

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04624
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26010:Metallic material properties-related
• Research Institution: Akita National College of Technology (2022-2023); Tohoku University (2021)
• Principal Investigator: Miura Daisuke 秋田工業高等専門学校, その他部局等, 准教授 (90708455)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 磁気異方性 / 有限温度磁性

Outline of Final Research Achievements

In this study, we have investigated ferromagnetic metals with uniaxial magnetic anisotropy and discussed the temperature dependence of various magnetic properties from microscopic viewpoints. Generally, it is difficult to apply itinerant-electron finite-temperature magnetism theory to materials with a high Curie temperature due to high computational load. We have solved this problem by using the coherent potential approximation and obtained the following results: (1) a realistic value was obtained for Curie temperatures. (2) the Curie-Weiss law in longitudinal and transverse magnetic susceptibilities was reproduced. (3) the Akulov-Zener-Callen-Callen law for the temperature dependence of the magnetocrystalline anisotropy was reproduced.

Free Research Field

磁性理論

Academic Significance and Societal Importance of the Research Achievements

近年，環境負荷が小さく且つ特定国に偏在しない磁性材料に対する社会的関心が高くなってきており，特に，重希土類を用いない実用材料の開拓が求められている．遷移金属合金は有力な候補の一つであるが，その有限温度磁気特性を理論的に記述することは困難であった．今回，実際にバンド理論によってこれを記述し，数値計算による実行可能性を示したことは，今後の物質設計における理論的基盤を築くために重要な成果であると考える．