Theoretical studies of spin-Hamiltonian parameters of Mo5+ ion doped in K2SnCl6 crystal

The spin-Hamiltonian (SH) parameters (g factors g//, g⊥ and hyperfine structure constants A//, A⊥ ) of K2SnCl6: Mo5+ (4d1) crystal are theoretically studied by the use of two microscopic spin-Hamiltonian (SH) methods, the high-order perturbation theory method (PTM) and the complete diagonalization (of energy matrix) method (CDM) within the molecular orbital (MO) scheme. The contributions arising both from the crystal field and charge transfer excitations are taken into account. The investigations show that the charge transfer mechanism plays a decisive role in the understanding of the spin-Hamiltonian (SH) parameters for 4d1 ions in crystals with the strong coordinate covalence, especially for g//>g⊥ which cannot be explained in the frame work of traditional crystal field approximation (CFA). The local defect structure around Mo5+ impurity ion center is determined to be D4 h point group symmetry.