Strain-induced magnetic anisotropy in Heusler alloys studied from first principles

We report the microscopic origin of strain-mediated changes in the magnetocrystalline anisotropy energy of the Co2FeSi, Co2MnSi, and Fe3Si Heusler alloys from the viewpoint of first-principles electron theory. Both Co2FeSi and Co2MnSi have similar anisotropy changes upon induced strain within the (001) plane, where the quadrupole moment due to Co minority-spin states dominates the anisotropy modulation, and, thus, giant magnetoelectric couplings in multiferroic heterointerfaces containing these compounds. In contrast, the strain-induced anisotropy modulation in Fe3Si has mixed contributing factors not limited to the anisotropy term of the orbital magnetic moment and the quadrupole term.

Automated summary

We investigate the microscopic origin of strain-induced changes in the magnetocrystalline anisotropy energy of Co2FeSi, Co2MnSi, and Fe3Si Heusler alloys using first-principles electron theory. The anisotropy modulation in Co2FeSi and Co2MnSi is dominated by the quadrupole moment of Co minority-spin states under strain within the (001) plane, leading to giant magnetoelectric couplings in multiferroic heterointerfaces containing these compounds. On the other hand, the strain-induced anisotropy modulation in Fe3Si has mixed contributing factors including the anisotropy term of the orbital magnetic moment and the quadrupole term.