The role of spin fluctuations in the anomalous anisotropy of MnBi

Joseph Barker, Oleg Mryasov

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


MnBi is unusual for having a magnetic anisotropy energy which increases with temperature. Recent theoretical works have studied how the lattice effects the anisotropy. However, the role of spin fluctuations has been hitherto overlooked, even though this is the primary mechanism for the temperature dependence of anisotropy in magnetic materials. We have created a model of MnBi including all anisotropy terms which are indicated from experiments and theory. Parameterizing based on experimental measurements we used the Callen-Callen theory to calculate the temperature dependence of the magnetic anisotropy due to spin fluctuations. An excellent agreement is found with experiments, across the entire temperature range. Our results indicate the driving force to be the competition between in-plane single ion and out of plane two-ion anisotropies.

Original languageEnglish
Article number484002
JournalJournal of Physics D: Applied Physics
Issue number48
Publication statusPublished - 2016 Nov 4


  • MnBi
  • anisotropy
  • theory

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films


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