The magnetic anisotropy energy of 13-atom Fe-Pt, Co-Pt and Ni-Pt clusters

The spin-orbital coupling (SOC) effect and magnetic anisotropy energy (MAE) of 13-atom Fe-Pt, Co-Pt and Ni-Pt clusters were investigated by density functional theory. The result shows that the Fe-Pt system has a higher MAE than Co-Pt and Ni-Pt. In the Fe8Pt5 cluster, the main contribution of MAE comes from SOC interaction between d orbitals around the Fermi level in Pt atoms. The giant positive MAE is mainly due to the SOC interaction between the majority spin states of d(x2) and d(xy) dxy orbitals.