Quantitative analysis of spin and orbital magnetic moments in a neodymium magnet by magnetic Compton scattering

Research Project

Project/Area Number	18K04686
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	Japan Synchrotron Radiation Research Institute
Principal Investigator	Tsuji Naruki 公益財団法人高輝度光科学研究センター, 回折・散乱推進室, 研究員 (90573113)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2020: ¥260,000 (Direct Cost: ¥200,000、Indirect Cost: ¥60,000) Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2018: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Keywords	磁性 / 磁気コンプトン散乱 / ネオジム磁石 / 保磁力 / 磁気ヒステリシス / スピン・軌道分離 / 放射光 / スピン軌道分離磁化測定
Outline of Final Research Achievements	The purpose of this study is to quantitatively analyze the temperature dependence of the spin and orbital magnetic moments and coercivity of neodymium magnets. We measured the coercivity of the spin moment using magnetic Compton scattering and its depth dependence. As a result, we observed that the coercivity decreased near the surface due to surface degradation by mechanical cutting and polishing. We also found that the coercivity decreased slightly at the center region of the magnet due to the demagnetizing field. We also measured the temperature dependence of the spin magnetization. It showed a different temperature dependence from the total magnetization measurement measured by the VSM.
Academic Significance and Societal Importance of the Research Achievements	高性能磁石は、ハイブリット自動車や電気自動車などのモータとして使用されるため、さらに高性能な磁石を開発することが求めらえれている。その開発には、磁石の磁気状態を詳細に観測することが必要不可欠であり、本研究では、磁石の詳細な磁気状態観測を行う方法を開発し、ネオジム磁石の磁気状態観測を行った。本研究での成果が、高性能磁石の開発に寄与することが期待される。