Dariush Souri

The direct current electrical conductivity of ternary 40TeO2–(60−x)V2O5–xMoO3 glasses prepared by press-melt quenching technique was studied at temperatures between 90 and 403K. From the conductivity–temperature relation, it was found that the small polaron hopping (SPH) model was applicable at the temperature above 2D/2 (2D: the Debye temperature), and the electrical conduction was due to the non-adiabatic SPH of electrons between vanadium ions for all glasses. The hopping carrier mobility and carrier density were determined at different temperatures. At temperatures lower than 2D/2, a T−1/4 dependence of the conductivity was found, which can be described by the variable-range hopping (VRH) conduction mechanism. The density of states at (or near) the Fermi level, N(EF), was found from Mott parameters analysis,which was a function of V2O5 content. All the semiconducting glass compositions exhibited a crossover from VRH to SPH conduction at a characteristic temperature TR > 2D/2.