材料期刊网

The spin Hamiltonian parameters, the g factors g(i) (i = x, y, z) and the hyperfine structure constants A(i), and the local structure for Rh(2+) in rutile (TiO(2)) are theoretically investigated from the perturbation formulas of these parameters for a 4d(7) ion under rhombically elongated octahedra. In view of the covalency, the ligand orbital and spin-orbit coupling contributions are taken into account from the cluster approach. The planar bond angle in the impurity center is found to be 7.5 degrees larger than that of the host Ti(4+) site because of the Jahn-Teller effect via bending of the planar Rh(2+)-O(2-) bonds, leading to much smaller rhombic distortion. The theoretical spin Hamiltonian parameters based on the above Jahn-Teller angular distortion show reasonable agreement with the experimental data.