Research of the spin-Hamiltonian parameters for the tetragonal Co2+ tetrahedral centers in Y3Al5O12 and Y3Ga5O12 crystals

In this article, the calculations with the high-order perturbation formulas founded on the two-spin-orbit-parameter (of dn ion and that of ligand) model are performed for the spin-Hamiltonian parameters (zero-field splitting D and g factors g//, g⊥) of the tetragonal Co2+ tetrahedral centers in Y3Al5O12 and Y3Ga5O12 crystals. The calculated results by using only one adjustable parameter are comparable with the experimental values. The impurity-caused angular distortions in the Co2+ centers in both crystals are also evaluated. The results are discussed.