Theoretical Studies of the Local Structures and EPR Spectra for VO²⁺in MB₄O₇(M = Zn, Cd) Glasses

Abstract

Electron spin resonance spectral parameters (g factors g , g ⊥ and hyperne structure constants A , A ⊥ ) of a tetragonal V 4+ centers in MB4O7 (M = Zn, Cd) are theoretically investigated by using the perturbation formulae for a 3d 1 ion in tetragonally compressed octahedra. In these formulae, the contributions to the g factors from the tetragonal distortion, characterized by the tetragonal eld parameters Ds and Dt are taken into account by considering the local structures of the ligand octahedron around the V 4+ due to the JahnTeller eect. Based on the calculations, the ligand octahedra around V 4+ are suggested to suer about 5.7% and 4.3% relative compression along C4 axis for MB4O7 glasses with M = Zn and Cd, respectively, and negative signs of the hyperne structure constants A and A ⊥ for V 4+ centers in MB4O7 glasses were suggested in the discussion.

Theoretical studies of the optical and EPR spectra for VO^{2+} in Na_{3}C_{6}H_{5}O_{7}·2H_{2}O single crystal

“…this is consistent with a number of theoretical investigations [4,9,[19][20][21][22] and the previous calculation [11]. Therefore, the above calculated A and A ⊥ of the hyperfine structure constants for TSCD:VO 2+ are reasonable in signs and in magnitude.…”

“…VO 2+ in various crystal [4,10,[19][20][21][22], here, we take κ ≈ 0.80, which is comparable with that κ (≈ 0.72) obtained by the previous work and can be regarded as reasonable. Thus, the g factors, especially the anisotropy ∆g (= g ∥ − g ⊥ ) is connected with the tetragonal field parameters and hence with the local structure (i.e., the relative tetragonal elongation R ∥ − R ⊥ ) of the studied systems.…”

“…Thus, the g factors, especially the anisotropy ∆g (= g ∥ − g ⊥ ) is connected with the tetragonal field parameters and hence with the local structure (i.e., the relative tetragonal elongation R ∥ − R ⊥ ) of the studied systems. Due to the covalence reduction effect for 3d n ions in crystals, we have [19][20][21][22] ζ = N 2 ζ 0 and P = N 2 P 0 .…”

Investigations on the Spin-Hamiltonian Parameters and Local Structure of the Orthorhombic Cu2+Center in PbTiO3Crystal

“…ζ and P are, respectively, the spinorbit coupling coecient and the dipolar hyperne structure parameter for the 3d 9 ion in crystals. Because of the covalence reduction eect for 3d n ions in crystals, we have [20,21]:…”