Structural and Polaronic transport properties of semiconducting CuO–V2O5–TeO2 glasses

Ternary semiconducting glasses in the CuO–V2O5–TeO2 system have prepared by the press-quenching technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), infrared (IR) spectra, density (d) and oxygen molar volume (Vm) and dc conductivity (σ) of these glasses were reported. The overall features of XRD curves confirm the amorphous nature of the present glasses. SEM exhibits a surface without any presence of microstructure which is a characteristic of the amorphous phase. Density was observed to decrease with an increase in V2O5 content. The network structure for the glass compositions with 57.5 mol% V2O5 is built up of the VO5 polyhedra, while the other glass compositions consist of VO4 polyhedra. The temperature dependence of the conductivity data has been analyzed in terms of different polaronic models. In high-temperature region above θD/2 the Mott model of SPH between nearest neighbors is consistent with the conductivity data, while at intermediate temperature the Greaves VRH (variable-range hopping) model was found to be appropriate. The conduction was confirmed to obey the adiabatic SPH and was mainly due to electronic transport between V ions. The dominant factor determining conductivity was the hopping carrier mobility in these glasses.