Theoretical investigations of the zero-field splitting and g factors for CdS : Ti 2+ and CdSe : Ti 2+ crystals

Abstract

The zero-field splitting D and g factors g || and g ⊥ for Ti 2+ ions in CdS and CdSe crystals are calculated from the high-order perturbation formulas of EPR parameters based on the two-spin–orbit (SO) coupling parameter model. In this model, the contributions to EPR parameters from both the SO coupling parameter of the central 3d 2 ion and that of the ligand are considered. The calculated results show good agreement with the observed values. Comparing these results with those calculated from the conventional one-SO-parameter model where the contributions only from the SO coupling parameter of the 3d 2 ion are considered, it suggests that the calculations of EPR parameters D, g || and g ⊥ for 3d 2 ions in tetrahedrally coordinated semiconductors should prefer the two-SO-parameter model over the one-SO-parameter model.