Site preference and magnetic properties of Ga/In-substituted strontium hexaferrite: An ab initio study

摘要

The first-principles density functional theory has been used to study Ga/ln-substituted strontium hexaferrite (SrFe_(12)O_(19)). Based on the calculation of the substitution energy of Ga and In in SrFe_(12)O_(19) and the formation probability analysis, we conclude that in SrFe_(12-x)Ga_xO_(19)the substituted Ga atoms prefer to occupy the 12k, 2a, and 4f_1 sites, while In atoms in SrFe_(12-x)In_xO_(19) occupy the 12k, 4f_2, and 4f_1 sites. We used the site occupation probabilities to calculate the magnetic properties of the substituted SrFe_(12)O_(19). It was found that as the fraction of Ga atoms in SrFe_(12-x)Ga_xO_(19) increases, the saturation magnetization (M_s) as well as magnetic anisotropy energy (MAE) decrease, while the anisotropy field (H_a) increases. In the case of SrFe_(12-x)In_xO_(19), M_s, MAE, and H_a decrease with an increase of the concentration of In atoms.