Magnetization reversal of exchange-coupled and exchange-decoupled Nd-Fe-B magnets observed by magneto-optical Kerr effect microscopy

被引：119

作者：

Soderznik, M. ^{[1
,2
]}

Sepehri-Amin, H. ^{[1
]}

Sasaki, T. T. ^{[1
]}

Ohkubo, T. ^{[1
]}

Takada, Y. ^{[3
]}

Sato, T. ^{[3
]}

Kaneko, Y. ^{[3
]}

Kato, A. ^{[4
]}

Schrefl, T. ^{[5
]}

Hono, K. ^{[1
]}

机构：

[1] Natl Inst Mat Sci, Tsukuba, Ibaraki 3050047, Japan

[2] Jozef Stefan Inst, Ljubljana 1000, Slovenia

[3] Toyota Cent Res & Dev Labs Inc, Nagakute, Aichi 4801192, Japan

[4] Toyota Motor Co Ltd, Adv Mat Engn Div, Susono 4101193, Japan

[5] Danube Univ, Ctr Integrated Sensor Syst, Krems, Austria

来源：

ACTA MATERIALIA | 2017年 / 135卷

基金：

日本学术振兴会;

关键词：

Nd-Fe-B magnet; Magnetic domains; Coercivity; Kerr microscopy; SINTERED NDFEB MAGNETS; GRAIN-BOUNDARY PHASE; PERMANENT-MAGNETS; HIGH-COERCIVITY; GA; MICROSTRUCTURE; TEMPERATURE;

D O I：

10.1016/j.actamat.2017.05.006

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We observed the magnetization reversals of exchange-coupled and exchange-decoupled Nd-Fe-B sintered magnets with coercivities of 1.16 and 1.80 T, respectively, by magneto-optical Kerr effect (MOKE) microscopy. The cascade propagation of reversed magnetic domain throughout multiple grains was observed, in the standard sintered magnet, in which Nd2Fe14B grains are believed to be exchange-coupled through ferromagnetic grain boundary phase. In the exchange-decoupled Nd-rich Ga-doped sintered magnet, the magnetization reversal is suppressed by thick nonmagnetic grain boundary phase. The EBSD revealed 11 misalignment of 2:14:1 grains in the standard sintered magnet, while higher misalignment of 18 was found in the exchange-decoupled Nd-rich Ga-doped magnet. Micromagnetic simulations incorporating such microstructural features reproduced experimentally observed demagnetization curves fairly well including the enhancement of the coercivity and the deterioration of the squareness in the exchange decoupled sintered magnet. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：68 / 76

页数：9

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