材料期刊网

The electron paramagnetic resonance (EPR) g factors g(i) (i = x,y,z) and the hyperfine structure constants A(i) for the rhombic Co2+ center in magnesium acetate are theoretically studied from the perturbation formulas of these parameters for a 3d(7) ion under rhombic symmetry. In these formulas, the contributions from the admixture among different states, covalency effect and rhombic crystal-fields are taken into account. The related crystal-field parameters are determined from the superposition model and the local geometrical relationship of the impurity center. The calculated results show reasonable agreement with the observed values. In addition, the nuclear quadrupole interaction constant is analyzed, and its negative sign is verified theoretically.