材料期刊网

The impurity displacements for Fe3+ and Ru3+ in corundum (Al2O3) are theoretically studied using the perturbation formulas of the spin Hamiltonian parameters (zero-field splitting and anisotropic g factors) for a 3d(5) (with high spin S = 5/2) and a 4d(5) (with low spin S = 1/2) ion in trigonal symmetry, respectively. According to the investigations, the nd(5) (n = 3 and 4) impurity ions may not locate at the ideal Al3+ site but undergo axial displacements by about 0.132 angstrom and 0.170 angstrom for Fe3+ and Ru3+, respectively, away from the center of the ligand octahedron along the C-3 axis. The calculated spin Hamiltonian parameters based on the above axial displacements show good agreement with the observed values. The validity of the results is discussed.