DC Conduction and Electric Modulus Formulation of Lithium-Doped Bismuth Zinc Vanadate Semiconducting Glassy System

Abstract

The conduction parameters related to dc conductivity and electric modulus formulation in the temperature range 313-533 K for xLi 2 O (100 - x) (50V 2 O 5. 20 Bi 2 O 3. 30 ZnO) glass system have been studied. The temperature-dependant dc conductivity is analyzed using the Mott's model for transition metals and modified Mott's VRH model. It is observed that Mott's model is in good agreement with the experimental data in high- and intermediate-temperature region as a strong electron-phonon interaction seems to be prevalent. The conduction in these glasses has been attributed to small polaron hopping at the vanadium sites in nonadiabatic regime. The ion-polaron effect (coupling between ions and polarons) leads to drop of the effective mobility and it can manifest itself as decrease in the dc conductivity with the addition of lithium content. The composition and temperature dependence of imaginary part of electric modulus (M″) collapsed onto a single master curve, confirms the presence of same type of relaxation phenomenon in all the studied glass compositions.