Calculation of magnetocrystalline anisotropy energy in NdCo5

Abstract

AbstractThe magnetocrystalline anisotropy energy (MAE) of NdCo5 was studied from first principles using the full potential linearized augmented plane wave (FLAPW) method. The LDA + U method was used to take into account the effects of strong electronic correlations of 4f states. In agreement with experiments, the magnetization points into the crystallographic a‐axis in the basal plane. The in‐plane MAE was also studied and the correct magnetization direction was arrived at but the magnetic anisotropy constant K3 was about one order of magnitude smaller than the experimental value. The microscopic origin of the MAE in NdCo5 was studied using the orbital moment anisotropy (OMA) and its evolution with lattice geometry. Spin‐reorientation transitions in NdCo5 could be well explained by the competition in OMA between Co and Nd sites. These results show that the non‐equivalent Co sites behave differently with changes in lattice geometry, and the Co3g sites are of the same importance as Nd sites in deciding the in‐plane magnetocrystalline anisotropy of NdCo5. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)