Prediction of a Larger Local Magnetic Anisotropy in Permalloy
(English)Manuscript (preprint) (Other academic)
By means of relativistic, first principles calculations, we investigate the microscopic origin of the vanishingly low magnetic anisotropy of Permalloy. Analyzing the local magnetic anisotropy of these alloys, we find that it can be several orders of magnitude larger than that of the bulk sample, and at least one order of magnitude larger than that of Fe or Ni. We discuss these results in terms of local symmetries of the alloy, and point out that an analysis based on perturbation theory has the spin-orbit coupling entering as a second-order term, as opposed to the naively expected fourth order contribution. The relevance for these findings in experiments, e.g. using pump-probe investigations, is discussed, as well as the implications for building effective spin-Hamiltonians of Permalloy.
magnetism, magnetic anisotropy
Research subject Physics with spec. in Atomic, Molecular and Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-304517OAI: oai:DiVA.org:uu-304517DiVA: diva2:1033177