Dielectric properties and conductivity studies of cuo doped borotellurite glasses

CuO doped borotellurite glasses, (B2O3)0.2-(TeO2)0.8-x-(CuO) x, ¬where x = 0.1, 0.2, 0.3, 0.4 and 0.5 were prepared by standard melt quenching method and their non-crystalline nature was confirmed by XRD studies. Dielectric properties as a function of frequency and temperature over the wide ranges have been measured. Observed decrease in dielectric constant and loss with increase in frequency and temperature has been ascribed to the decrease in ionic contribution. Dielectric parameters increased with increase in CuO content. Conductivity was estimated from dielectric data. The high temperature electrical conductivity has been analyzed using Mott’s small polaron model and activation energy was determined. Activation energy decreased and conductivity increased with increase in CuO content. Conductivity also increased with increase in frequency. Frequency exponent of conductivity is found to be temperature dependent, and this contradicted Quantum mechanical tunneling (QMT) model’s prediction. It is for the first time that CuO doped borotellurite glasses have been investigated for frequency dependent dielectric properties and ac conductivity and data analysed thoroughly.