Searching the weakest link: Demagnetizing fields and magnetization reversal in permanent magnets

SCRIPTA MATERIALIA

卷:154

Article

Fischbacher, J.¹  Kovacs, A.¹  Exl, L.^2,3  Kuehnel, J.⁴  Mehofer, E.⁴  Sepehri-Amin, H.⁵  Ohkubo, T.⁵  Hono, K.⁵  Schrefl, T.¹ 

[1] Danube Univ Krems, Ctr Integrated Sensor Syst, Viktor Kaplan Str 2,Bauteil E, A-2700 Wiener Neustadt, Austria

[2] Univ Vienna, Fac Phys, A-1090 Vienna, Austria

[3] Univ Vienna, Fac Math, A-1090 Vienna, Austria

[4] Univ Vienna, Fac Comp Sci, A-1090 Vienna, Austria

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

关键词: Permanent magnet;    Micromagnetism;    Grain boundary diffusion;   

DOI  :  10.1016/j.scriptamat.2017.11.020

来源: Elsevier

【 摘 要 】

Magnetization reversal in permanent magnets occurs by the nucleation and expansion of reversed domains. Micromagnetic theory offers the possibility to localize the spots within the complex structure of the magnet where magnetization reversal starts. We compute maps of the local nucleation field in a Nd2Fe14B permanent magnet using a model order reduction approach. Considering thermal fluctuations in numerical micromagnetics we can also quantify the reduction of the coercive field due to thermal activation. However, the major reduction of the coercive field is caused by the soft magnetic grain boundary phases and misorientation if there is no surface damage. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free