Electrical characterization of lead-modified bismuth borovanadate glasses

Abstract

Specifically, the study looks into dielectric characteristics (${\epsilon }^{\prime }\text{and}{\epsilon }^{″}$) and complex modulus formulation and AC conductivity of lead-modified bismuth borovanadate glasses (50-x) V₂O₅-40 B₂O₃-10 Bi₂O₃-xPbO, where x = 5,10, 15, 20 and 25 mol% with sample ID's VPb1, VPb2, VPb3, VPb4 & VPb5 according to different compositions of lead and vanadate. When the PbO content rises, there is a decreasing tendency in both the alternating current conductivity and dielectric constants. In order to fit AC conductivity data, Almond West equation is used to extract parameters, including crossover frequency (${\omega }_H$), frequency exponent (s), and direct current conductivity (${\sigma }_{dc})$. Direct current conduction mechanism in all glass samples except VPb5 [Correlated Barriers Hopping (CBH) conduction at all frequencies] at lower frequencies might potentially be attributed to large-polaron quantum mechanical tunneling (LQMT). Similar to this, at high frequencies, small polaron quantum mechanical tunnelling is followed by VPb2 & VPb3 while LQMT is followed by VPb1 & VPb4. Activation energy of dc conduction ($E_{\text{dc}}$) at higher frequencies (0.373–0.476 eV) for samples having sample ID VPb1 to VPb4 and sample VPb5 at all frequencies with $E_{\text{dc}}$ 0.686 eV and modulus activation energy $\left(E_R\right)$ (0.382–0.534 eV) are found in good agreement. Dielectric studies reveal non-Debye-type behaviour.