EPR parameters and local lattice structure study of V~(2+) ions in CdCl_2 and CsMgCl_3 crystals

摘要

The local lattice structure and EPR parameters (D, g_(||), g _⊥) have been studied systematically on the basis of the complete energy matrix for a d~3 configuration ion in a trigonal ligand field. By simulating the calculated optical and EPR spectra data to the experimental results, the local distortion parameters (ΔR, Δθ) are determined for V~(2+) ions in CdCl_2 and CsMgCl_3 crystals, respectively. The results show that the local lattice structure of CdCl_2:V~(2+) system exhibits a compression distortion (ΔR=-0.0868 ?) while that of CsMgCl_3:V~(2+) system exists an elongation distortion (ΔR=0.0165 ?). The different distortion may be ascribed to the fact that the radius of V~(2+) ion is smaller than that of Cd~(2+) ion or larger than that of Mg~(2+) ion. Moreover, the relationships between EPR parameter D and local structure parameters (R, θ) as well as the orbital reduction factor k and gfactors (g_(||), g_⊥) are discussed.