Investigations of the Anisotropic g Factors for Co²⁺ in CaTiO₃

The anisotropic g factors gx, gy and gz for Co2+ in CaTiO3 are theoretically investigated from the perturbation formulas of the g factors for a 3d7 ion in orthorhombically distorted octahedra based on the cluster approach. The related orthorhombic field parameters are determined from the local structure of the studied impurity center and the superposition model. Because the impurity Co2+ differs from the host Ti4+ in ionic radius and charge, the Co-O band lengths along two directions may suffer a relative variation by about 5.6%, yielding significant orthorhombic distortion. The calculated g factors by using the above local structure are in reasonable agreement with the experimental findings.