材料期刊网

The anisotropy spin-orbit coupling matrices for a d(5) configuration ion in a trigonal ligand-field have been established. On basis of the anisotropy spin-orbit coupling matrices, the ground state zero-field splitting of the Fe3+ ions in ilmenite-structure MgTiO3:Fe3+ system has been studied. The calculated results show that the anisotropy of Fe3+ ions in the diamagnetic ilmenite MgTiO3 is important and the EPR parameters depend sensitively on the anisotropy divergent parameter. Moreover, the effect of the anisotropy divergent parameter on the second-order parameter D is obviously larger than that on the fourth-order parameter (a-F). Based on this point, the local lattice structure of Fe3+ ion in MgTiO3:Fe3+ system is determined by diagonalizing the complete energy matrices for a d(5) configuration ion in a trigonal ligand-field and considering the second-order as well as the fourth-order EPR parameters D and (a-F) simultaneously. Our results are consistent with the experimental proposal that Fe3+ ions may locate at both the Mg2+ and Ti4+ Sites.