Magnetic-field-induced selective retardation of reaction in Mn/Ga diffusion couple

[摘要] In-field heat treatments of a solid-liquid Mn/Ga diffusion couple were conducted at 573 and 673 K with and without a magnetic field of 5 T to investigate magnetic field effects on the phase formation. Formation of the beta-Mn, Mn3Ga, gamma-MnGa, lambda-MnGa, Mn2Ga5, and MnGa4 phases was observed. The obtained results indicated that the reaction and phase growth of lambda-MnGa and Mn2Ga5 proceeded by diffusion-controlled process for both heat treatments at 0 and 5 T. We confirmed that a magnetic field suppressed the phase growth of lambda-MnGa and Mn2Ga5. The parabolic coefficients of the lambda-MnGa and Mn2Ga5 phases were exponentially suppressed by applying magnetic field of 5 T. It is suggested that gain of Zeeman energy of Mn-rich phase played a key role for the magnetic-field-induced suppression of the formation of the lambda-MnGa and Mn2Ga5 phases. (C) 2021 Elsevier B.V. All rights reserved.

[发布日期] 2021-12-20

[关键词] Liquid-solid reactions;Diffusion;High magnetic fields;Magnetically ordered materials;Transition metal alloys and compounds