Theoretical studies on the gyromagnetic factors for Fe~(3+) in ZnX (X = O, S, Se, Te)

摘要

The gyromagnetic factors for Fe~(3+) in ZnX (X=O, S, Se, Te) are theoretically studied from the perturbation formula of the g-factor for a 3d~5 ion in tetrahedra based on inclusion of both the crystal-field and the charge-transfer contributions. The related model parameters in the calculations are determined from the cluster approach in a uniform way. The g-shift g (Δ= g-g_s, where g_s ≈ 2.0023 is the spin-only value) from the charge-transfer contributions is opposite (positive) in sign and much larger in magnitude as compared with that from the crystal-field ones. The importance of the charge-transfer contributions increases rapidly with increasing the covalency and the spin-orbit coupling coefficient of the ligand and thus exhibits the order of O~(2-) < S~(2-) < Se~(2-) < Te~(2-). The calculated g-factors by considering both the crystal-field and charge-transfer contributions show reasonable agreement with the experimental data for all the Fe~(3+) centers in ZnX.