In:
Microscopy and Microanalysis, Oxford University Press (OUP), Vol. 5, No. S2 ( 1999-08), p. 26-27
Abstract:
Performance of permanent magnets for a variety of applications is often determined by the maximum energy product (BH)max. In order to obtain high (BH)max permanent magnetic materials have to have large coercivity. In theory the coercive field of ideally oriented, non-interacting, single domain, magnetic particles, assuming Kl is much bigger than K2, was shown to be He = 2K1/Ms - N Ms, where Kl and K2 are the magnetocrystalline anisotropy constants, Ms is the spontaneous magnetization and N is the demagnetization factor. For randomly oriented non-interacting particles the Stoner-Wohlfarth model predicts that the value of Hc decreases to about half. However, experimentally obtained values of the coercitive fields in permanent magnets are 3 to 10 and 2 times smaller for well oriented and randomly oriented samples, respectively. This discrepancy was attributed to inter-particle interaction and the microstructure of the permanent magnets. In order to understand the difference between the theoretically predicted and experimentally obtained results for He we prepared rapidly quenched, Nd-rich, Nd x Fe 14 B (2 〈 x 〈 150) ribbons.
Type of Medium:
Online Resource
ISSN:
1431-9276
,
1435-8115
DOI:
10.1017/S1431927600013453
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
1999
detail.hit.zdb_id:
1481716-0
SSG:
11
SSG:
12
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