Studies on the local structure and spin Hamiltonian parameters for V 4+ in Na 2 O–PbO–Bi 2 O 3 –SiO 2 glass ceramics

The local structure, d–d transition band, and spin Hamiltonian parameters (SHPs) are theoretically studied for the V 4+ probe in Na 2 O–PbO–Bi 2 O 3 –SiO 2 (NPBS) glass ceramics containing V 2 O 5 dopant with various concentration x (0 ≤ x ≤ 5 mol%) by using the perturbation formulas of the SHPs for tetragonally compressed octahedral 3d 1 clusters. The first decreasing (or increasing) and then increasing (or decreasing) d–d transition band (= 10 D q ) and hyperfine structure constants A // and A ⊥ (or g factors g // and g ⊥ ) with x can be suitably simulated with the similarly varying Fourier type concentration functions of cubic field parameter D q , covalence factor N , core polarization constant κ , and reduction factor H (or relative tetragonal compression ratio ρ ), with the minima (or maxima) at the middle concentration x = 3 mol%, respectively. The above concentration variations of SHPs and the related quantities may originate from the modifications of local crystal field strength, tetragonal compression, and electron cloud distribution near the impurity V 4+ with x , corresponding to the highest [V 4+ ]/[V 5+ ] ratio at 3 mol%. Present studies would be helpful to explore novel sodium lead bismuth silicate glass ceramics by modifying the concentration of V 2 O 5 dopant.