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

H. Sepehri-Amin; T. Ohkubo; M. Gruber; T. Schrefl; K. Hono

doi:10.1016/j.scriptamat.2014.06.020

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

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

Research output: Contribution to journal › Article › peer-review

125 Citations (Scopus)

Abstract

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 μm, a higher magnetic field is needed to magnetize them, giving rise to a two-step initial magnetization curve.

Original language	English
Pages (from-to)	29-32
Number of pages	4
Journal	Scripta Materialia
Volume	89
DOIs	https://doi.org/10.1016/j.scriptamat.2014.06.020
Publication status	Published - 2014 Oct 15
Externally published	Yes

Keywords

Coercivity
Demagnetization field
Micromagnetic simulations
Nd-Fe-B sintered magnets

ASJC Scopus subject areas

Materials Science(all)
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering
Metals and Alloys

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10.1016/j.scriptamat.2014.06.020

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

abstract = "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 μm, a higher magnetic field is needed to magnetize them, giving rise to a two-step initial magnetization curve.",

keywords = "Coercivity, Demagnetization field, Micromagnetic simulations, Nd-Fe-B sintered magnets",

author = "H. Sepehri-Amin and T. Ohkubo and M. Gruber and T. Schrefl and K. Hono",

note = "Funding Information: This work was supported by the Japan Science and Technology Agency (JST), CREST . ",

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doi = "10.1016/j.scriptamat.2014.06.020",

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T1 - Micromagnetic simulations on the grain size dependence of coercivity in anisotropic Nd-Fe-B sintered magnets

AU - Sepehri-Amin, H.

AU - Ohkubo, T.

AU - Gruber, M.

AU - Schrefl, T.

AU - Hono, K.

N1 - Funding Information: This work was supported by the Japan Science and Technology Agency (JST), CREST .

PY - 2014/10/15

Y1 - 2014/10/15

N2 - 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 μm, a higher magnetic field is needed to magnetize them, giving rise to a two-step initial magnetization curve.

AB - 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 μm, a higher magnetic field is needed to magnetize them, giving rise to a two-step initial magnetization curve.

KW - Coercivity

KW - Demagnetization field

KW - Micromagnetic simulations

KW - Nd-Fe-B sintered magnets

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DO - 10.1016/j.scriptamat.2014.06.020

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EP - 32

JO - Scripta Materialia

JF - Scripta Materialia

SN - 1359-6462

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

Abstract

Keywords

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