THEORETICAL STUDIES ON THE GYROMAGNETIC FACTORS FORFe3+INZnX(X=O,S,Se,Te)

Abstract

The gyromagnetic factors for Fe3+in ZnX ( X = O , S , Se , Te ) are theoretically studied from the perturbation formula of the g-factor for a 3d5ion 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 Δg (= g-gs, where gs≈ 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 O2-< S2-< Se2-< Te2-. The calculated g-factors by considering both the crystal-field and charge-transfer contributions show reasonable agreement with the experimental data for all the Fe3+centers in ZnX .