Theoretical explanations of magnetocrystalline anisotropy behaviors in <i>R</i>TiFe11N<i>x</i> compounds

Abstract

The RTiFe11Nx compounds have higher Curie temperatures, larger saturation magnetization, and entirely different magnetocrystalline anisotropy behavior as compared with the RTiFe11 compounds. In contrast to RTiFe11, the c axis becomes the easy magnetization direction of RTiFe11Nx when R=Nd, Tb, Dy, and Ho, while SmTiFe11Nx has an easy plane and ErTiFe11Nx presents a spin reorientation at about 45 K. Theoretical calculations were made to explain those anisotropy behaviors. The calculation results show that the changes in anisotropy behaviors could be attributed to the large positive contribution of nitrogen atoms located at 2b interstitial sites to the second-order crystal-field coefficient A20.