An investigation of spin-Hamiltonian parameters for Pd~(2+) ions in trigonal sites of CsMgCl_3 crystals

摘要

The spin-Hamiltonian (SH) parameters, g factors g//, g union and zero-field splitting D, for Pd~(2+) (4d~8) ions in trigonal sites of CsMgCl_3 crystals are calculated from the complete diagonalization (of energy matrix) method (CDM) and the perturbation theory method (PTM). The results from both CDM and PTM are not only close to each other, but also in agreement with the experimental values. The very small trigonal distortion of Pd~(2+) impurity center in CsMgCl_3 crystal is acquired from the calculation. The reasons that the small differences between the calculated SH parameters, particularly, the zero-field splitting D, from PTM and CDM are discussed. On the basis of this, the PTM can be used for approximate estimations of SH parameters for Pd~(2+) (4d~8) centers in crystals with same trigonal distortion. However, it is unadvisable in the studies of SH parameters for 5d~8 Pt~(2+) and Au~(3+) centers in crystals even with small trigonal distortion because of the very large spin-orbit coupling parameters xi_0 (approx = 4626 and 5640 cm~(-1) for Pt~(2+) and Au~(3+), respectively).