The covalence effect of the gyromagnetic factor of CdS:Co2+

In this paper, formulas for the optical spectrum and the gyromagnetic factor for d7 ions in Td symmetry with a slight triangle perturbation are established by using a covalent model, in which the covalence contribution has been considered. Using the model, we have calculated the optical spectra and the g-factor of CdS:Co2+. The calculation results agree well with the experimental findings. It suggests that covalent model should be adopted for the calculation of the optical spectrum and the EPR parameters for Co2+ ion in covalent crystal.