Abstract
The magnetocrystalline anisotropy and its temperature dependence of ordered Au4Mn has been measured by the torque method utilizing a single crystal. The magnetic easy direction was determined to be the tetragonal [001] axis.
The four-fold torque amplitude first increases and then decreases with increasing field strength. This behavior can be understood as an effect of a twin structured model of the ordered Au4Mn, and the torque curves at various temperatures can be analyzed on the basis of this model. The uniaxial anisotropy energy at absolute zero has been determined to be 30×105 erg/cc, and the temperature dependence has been found to be proportional to ⟨S2⟩, which indicates that the Mn spin of the Au4Mn is of a localized state.
