Theoretical analysis on lead halides content dependences of defect structures and spin Hamiltonian parameters in lead halo borate glass composites with V2O5 dopants

Abstract

The defect structures and spin Hamiltonian parameters (SHPs) for V4+ in lead halo borate (xPbX2–(30 − x)PbO–68B2O3, X = F, Cl, Br and x = 5, 10, 15, 20 and 25 mol%) glass composites containing 2 mol% of V2O5 dopant are theoretically studied by applying the perturbation formulas of the SHPs for tetragonally compressed octahedral 3d1 clusters. The experimental SHPs are suitably reproduced by the optimal covalency factor N, relative tetragonal compression ratio ρ, core polarization constant κ and reduction factor H at various x, which are simulated with the corresponding Fourier type content functions. The distinct deviations of these quantities from the relevant simulated Fourier type content functions at 5 mol% of PbCl2 and PbBr2 are reasonably explained from the modifications of compactness and electronic cloud redistributions around V4+ at this content. This is supported by the previous analysis on the content variations of ionic conductivity of the systems.