Graded permanent magnets

R. Skomski, G. C. Hadjipanayis, David J Sellmyer

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

The effect of semihard magnetic phases and interfaces on the performance of nanostructured two-phase permanent magnets is investigated by model calculations. In addition to the trivial coercivity increase due to the replacement of soft regions by semihard regions, there is a coercivity enhancement even if the volume-averaged anisotropy is kept constant during the introduction of the semihard phase. A variational approach is used to derive analytical results for representative anisotropy profiles. The improvement is operative on length scales slightly larger than that of the soft phase in hard-soft composites, but the main challenge is to find semihard light or heavy transition metal phases with a high magnetization. There are several Fe- and Co-based phases, but most are thin-film systems and difficult to use in bulk magnets. Very hard nanostructured magnets may also be created from soft phases with negative but large anisotropy constants (hard-magnetic soft-soft magnets).

Original languageEnglish (US)
Article number07A733
JournalJournal of Applied Physics
Volume105
Issue number7
DOIs
StatePublished - Apr 27 2009

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permanent magnets
magnets
anisotropy
coercivity
heavy metals
transition metals
magnetization
composite materials
augmentation
thin films
profiles

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Graded permanent magnets. / Skomski, R.; Hadjipanayis, G. C.; Sellmyer, David J.

In: Journal of Applied Physics, Vol. 105, No. 7, 07A733, 27.04.2009.

Research output: Contribution to journalArticle

Skomski, R, Hadjipanayis, GC & Sellmyer, DJ 2009, 'Graded permanent magnets', Journal of Applied Physics, vol. 105, no. 7, 07A733. https://doi.org/10.1063/1.3068622
Skomski, R. ; Hadjipanayis, G. C. ; Sellmyer, David J. / Graded permanent magnets. In: Journal of Applied Physics. 2009 ; Vol. 105, No. 7.
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