Role of WO3 on DC conductivity and some optical properties of TeO2 based glasses

DC electrical conductivity and optical absorption studies have been employed to understand the influence of WO3 content on the electrical and optical properties of the TeO2-GeO2-WO3 glass system. Field emission scanning electron microscope (FESEM), Energy dispersive X-ray spectrometry (EDS) measurements have been used to confirm the glassy nature and the elemental analysis of the glass composition, respectively. DC electrical conductivity of the glasses was studied in the temperature range 423-613 K. From Arrhenius plot, the activation energies (E-act) of all the glasses have been calculated and conduction mechanism has been discussed in terms of structural changes occurred with the addition of WO3 content. The optical properties such as optical band gap (E-opt), Urbach energy (Delta E), molar refraction (R-M), metallization criterion (M), electronic polarizability of the oxide ion (alpha(o2-)) and refractive index (n) have been determined from optical absorption data and were found to be composition dependent. (c) 2012 Elsevier Ltd. All rights reserved.