Control of the Atomic Order of Magnetic Materials by Magnetic-field-induced Enhancement of the Reaction

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15016
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26010:Metallic material properties-related
• Research Institution: Kagoshima University
• Principal Investigator: Mitsui Yoshifuru 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: 規則合金 / 強磁場 / 規則-不規則変態 / 磁性

Outline of Final Research Achievements

Ni2MnAl and Mn2NiGa Heusler alloys have different magnetism with their order degree. In this study, magnetic field effects on ordering on these Heusler alloys were investigated. In Ni2MnAl, in-magnetic-field annealing was performed at 673 K and 623 K, which was below order-disorder transformation temperature. It is found that ordering to ferromagnetic L21 phase was accelerated by magnetic field. Meanwhile, in-magnetic-field annealing at 773 K was carried out for ferrimagnetic Mn2NiGa. At annealing at 773 K, Mn-rich phase precipitated in the Heusler matrix. It is suggested that in-magnetic-field annealing is effective for phase fraction of Mn-rich phase. Therefore, in this study, in-magnetic-field annealing is a useful method for controlling the ordering and precipitations in magnetic ordered alloys.

Free Research Field

磁気機能材料

Academic Significance and Societal Importance of the Research Achievements

本研究は、規則度によって磁性が異なる規則合金の規則化を磁場中熱処理によって制御することを目的とした。規則不規則変態温度が低いことで通常熱処理では規則化に長時間かかる場合や、第２相の析出によって物質合成が困難な場合において、磁場中熱処理によって規則化や析出物の制御が可能なことが示された。このことは、磁性合金の合成に磁場中熱処理が有用な方法であることを示唆しており、物質科学における意義は大きいと考えられる。