材料期刊网

In this paper, we establish the calculation formulas of g factors g(parallel to), g(perpendicular to) and the hyperfine structure constants A(parallel to), A(perpendicular to), for 3d(7) ions in tetragonal octahedral field from a cluster approach. In these formulas, besides the configuration interaction, the covalency effect due to the admixture between d electrons of 3d(7) ion and the p electrons of ligands is considered:d. The parameters used in these formulas (except the core polarization constants k in the calculation of A(i)) can be obtained from optical spectra of the studied crystal. From these formulas, the local release (or elongation) factor k, which is introduced to characterize the release effect of impurity-ligand bond along C-4 axis at the cubic to tetragonal phase transition, is estimated for CsCaCl3:Co2+ crystal by calculating the electronic paramagnetic resonance (EPR) parameters g(i) and A(i). These EPR parameters are therefore explained reasonably and the results are discussed.