Micromagnetic simulations on the grain size dependence of coercivity in anisotropic Nd-Fe-B sintered magnets

SCRIPTA MATERIALIA

卷:89

Article

Sepehri-Amin, H.¹  Ohkubo, T.¹  Gruber, M.¹  Schrefl, T.²  Hono, K.¹ 

[1] Natl Inst Mat Sci, Elements Strategy Initiat Ctr Magnet Mat, Tsukuba, Ibaraki 3050047, Japan

[2] St Polten Univ Appl Sci, St Polten, Austria

关键词: Micromagnetic simulations;    Nd-Fe-B sintered magnets;    Coercivity;    Demagnetization field;   

DOI  :  10.1016/j.scriptamat.2014.06.020

来源: Elsevier

【 摘 要 】

Micromagnetic simulations of magnetization reversals of Nd-Fe-B anisotropic magnets with exchange-coupled grains demonstrate that the local demagnetization factor decreases as the grain size is reduced. This explains the higher coercivity and the lower temperature dependence of coercivity in magnets with smaller grain sizes. When a fraction of Nd2Fe14B grains become a single domain state for average grain sizes <1 mu m, a higher magnetic field is needed to magnetize them, giving rise to a two-step initial magnetization curve. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free