Hysteresis and relaxation in granular permanent magnets

Ralph Skomski, B. Balamurugan, Tom A. George, Mircea Chipara, Xiao Hui Wei, Jeff E. Shield, D. J. Sellmyer

Research output: Contribution to journalArticle

Abstract

Some nontrivial aspects of the magnetic and structural characterization of hard-magnetic nanoparticles are investigated. Dilute ensembles are well-described by mean-field theory, although there is an asymmetry between exchange and magnetostatic interaction fields. Corrections to the mean-field approximation are caused by cooperative effects and have the character of Onsager reaction fields, which are much stronger in micromagnetism than in atomic-scale magnetism. The slow dynamics of zero-field-cooled (ZFC) magnetization curves is strongly affected by the particles′ magnetic anisotropy, which reduces the corresponding energy-barrier height from 25 to 19.1 k BT.

Original languageEnglish (US)
Article number07B507
JournalJournal of Applied Physics
Volume111
Issue number7
DOIs
StatePublished - Apr 1 2012

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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    Skomski, R., Balamurugan, B., George, T. A., Chipara, M., Wei, X. H., Shield, J. E., & Sellmyer, D. J. (2012). Hysteresis and relaxation in granular permanent magnets. Journal of Applied Physics, 111(7), [07B507]. https://doi.org/10.1063/1.3672845