Polaronic conduction and dielectric relaxation dynamics in V2O5 added lead bismuth silicate glass system

Dielectric Relaxation Dynamics and Polaronic Tunneling Conduction Mechanism of Electrical Conductivity of Fe2O3‐Doped PbO–ZrO2–SiO2 Glass Ceramics

“…Regarding the nature of the dipoles, the complexes of Fe 2+ ions with oxygens are predicted to act as dipoles. [ 3,26,27 ] In addition, the anisotropic crystal phases mentioned earlier do possess net‐electric dipole moment and contribute to the dipolar relaxation phenomenon. The spreading of relaxation is because of variations in the magnitudes of dipole moments of these dipoles.…”

“…A huge number of studies were performed on different amorphous systems along these lines in the recent years. [ 1–6 ]…”

Theoretical investigations on the defect structures and g factors for V4+ in 30PbO‐5Bi2O3‐(65‐x)SiO2 glasses at different concentrations

“…In order to analyze the observed g factors, [ 8 ] the perturbation formulas of g factors for 3d 1 ions in tetragonally compressed octahedra [ 26,37 ] can be adopted here: Here, g s ≈ 2.0023 is the free electron gyromagnetic value. [ 24 ] ζ and ζ′ are the spin‐orbit coupling parameters, and k and k′ are the orbital reduction coefficients.…”

“…Therefore, investigations for lead bismuth silicate glasses based on the V 4+ probes can reveal important local structural and electronic properties and are of special scientific significance. For instance, 30PbO‐5Bi 2 O 3 ‐(65‐x)SiO 2 (PBS) glasses doped with different concentrations x of V 2 O 5 (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 mol%) were prepared and measured with optical absorption and EPR techniques by Annapurna et al [ 8 ] The optical absorption measurements exhibited that the d‐d ( 2 B 2g → 2 B 1g ) transition band of V 4+ first increases from 14,814 cm −1 at 0.1 mol% to 15,151 cm −1 at 0.3 mol% and then decreases monotonically to 14,577 cm −1 at 0.6 mol%. [ 8 ] The measured EPR signals also revealed the fluctuations of g factors, that is, g || first decreases from 1.918 at 0.1 mol% to 1.915 at 0.3 mol% and then monotonically increases to 1.925 at 0.6 mol%, while g ⊥ first increases monotonically from 1.981 at 0.1 mol% to 1.985 at 0.4 mol% and then almost remains the same at the higher x.…”

“…For instance, 30PbO‐5Bi 2 O 3 ‐(65‐x)SiO 2 (PBS) glasses doped with different concentrations x of V 2 O 5 (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 mol%) were prepared and measured with optical absorption and EPR techniques by Annapurna et al [ 8 ] The optical absorption measurements exhibited that the d‐d ( 2 B 2g → 2 B 1g ) transition band of V 4+ first increases from 14,814 cm −1 at 0.1 mol% to 15,151 cm −1 at 0.3 mol% and then decreases monotonically to 14,577 cm −1 at 0.6 mol%. [ 8 ] The measured EPR signals also revealed the fluctuations of g factors, that is, g || first decreases from 1.918 at 0.1 mol% to 1.915 at 0.3 mol% and then monotonically increases to 1.925 at 0.6 mol%, while g ⊥ first increases monotonically from 1.981 at 0.1 mol% to 1.985 at 0.4 mol% and then almost remains the same at the higher x. [ 8 ] However, the quantitative local structural information for the V 4+ impurity has not been obtained so far, and the concentration dependences of the measured d‐d transition band and g factors as well as the defect structure have not been theoretically clarified either.…”