Element-specific analysis of the magnetic anisotropy in Mn-based antiferromagnetic alloys from first principles

The magnetic anisotropy energy (MAE) and element-specific contributions to the MAE have been studied for Mn-based antiferromagnetic alloys with layered L1(0) structure within the framework of the local spin-density approximation and the fully relativistic torque method. It is found that the contribution to the total MAE from nonmagnetic 3d and 4d elements in MnNi and MnPd alloys are comparable to the contribution of the magnetic Mn atoms. In the 3d-5d MnIr and the 4d-5d MnRh alloys the Ir and Rh contributions are found to be dominating. The origin of this nonzero contribution into the MAE from the atom with zero spin moment is linked to the nontrivial atomic spin density distribution, which gives a zero moment only on average. We also find and discuss the strong dependence of the total and element-specific contributions to the MAE on the state of magnetic order.