Effect of Grain Size on the Coercivity of Sintered NdFeB Magnets

Marcos Flavio de Campos

doi:10.4028/www.scientific.net/MSF.660-661.284

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HomeMaterials Science ForumMaterials Science Forum Vols. 660-661Effect of Grain Size on the Coercivity of Sintered...

Effect of Grain Size on the Coercivity of Sintered NdFeB Magnets

Abstract:

Sintered NdFeB magnets typically exhibit grain size above 2 micrometers, a value above the single domain particle size (~0.3 micrometers). It is discussed how to obtain relationships between grain size and coercivity with energy balance models, considering formation and annihilation of domain walls as a dissipative process. In the case of nanocrystaline magnets, the Stoner-Wohlfarth model is very suitable. For larger grain sizes, the contribution of the magnetostatic energy of each grain has to be considered. From the concept of meta-stability of domains and domain walls structure, a relation between coercive field and grain size can be estimated.

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Materials Science Forum (Volumes 660-661)

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284-289

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https://doi.org/10.4028/www.scientific.net/MSF.660-661.284

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October 2010

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Marcos Flavio de Campos

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Coercivity, Domain Wall, Grain Size, Magnet

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