TY - JOUR
T1 - Temperature dependence of the threshold magnetic field for nucleation and domain wall propagation in an inhomogeneous structure with grain boundary
AU - Mohakud, Sasmita
AU - Andraus, Sergio
AU - Nishino, Masamichi
AU - Sakuma, Akimasa
AU - Miyashita, Seiji
N1 - Funding Information:
The present work was supported by Grants-in-Aid for Scientific Research C (Grants No. 25400391 and No. 26400324) from MEXT of Japan and the Elements Strategy Initiative Center for Magnetic Materials under the outsourcing project of MEXT. The numerical calculations were supported by the supercomputer center of the ISSP of the University of Tokyo. S.M. would like to acknowledge DST, government of India, for an INSPIRE faculty award and research funding.
Publisher Copyright:
© 2016 American Physical Society.
PY - 2016/8/30
Y1 - 2016/8/30
N2 - In order to study the dependence of the coercive force of sintered magnets on temperature, nucleation and domain wall propagation at the grain boundary are studied as rate-determining processes of the magnetization reversal phenomena in magnets consisting of bulk hard magnetic grains contacting via grain boundaries of a soft magnetic material. These systems have been studied analytically for a continuum model at zero temperature [A. Sakuma, J. Magn. Magn. Mater. 84, 52 (1990)JMMMDC0304-885310.1016/0304-8853(90)90162-J]. In the present study, the temperature dependence is studied by making use of the stochastic Landau-Lifshitz-Gilbert equation at finite temperatures. In particular, the threshold fields for nucleation and domain wall propagation are obtained as functions of ratios of magnetic interactions and anisotropies of the soft and hard magnets for various temperatures. It was found that the threshold field for domain wall propagation is robust against thermal fluctuations, while that for nucleation is fragile. The microscopic mechanisms of the observed temperature dependence are discussed.
AB - In order to study the dependence of the coercive force of sintered magnets on temperature, nucleation and domain wall propagation at the grain boundary are studied as rate-determining processes of the magnetization reversal phenomena in magnets consisting of bulk hard magnetic grains contacting via grain boundaries of a soft magnetic material. These systems have been studied analytically for a continuum model at zero temperature [A. Sakuma, J. Magn. Magn. Mater. 84, 52 (1990)JMMMDC0304-885310.1016/0304-8853(90)90162-J]. In the present study, the temperature dependence is studied by making use of the stochastic Landau-Lifshitz-Gilbert equation at finite temperatures. In particular, the threshold fields for nucleation and domain wall propagation are obtained as functions of ratios of magnetic interactions and anisotropies of the soft and hard magnets for various temperatures. It was found that the threshold field for domain wall propagation is robust against thermal fluctuations, while that for nucleation is fragile. The microscopic mechanisms of the observed temperature dependence are discussed.
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U2 - 10.1103/PhysRevB.94.054430
DO - 10.1103/PhysRevB.94.054430
M3 - Article
AN - SCOPUS:84986000688
VL - 94
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 5
M1 - 054430
ER -