AC conductivity of unconventional bismuth cuprate glass

The frequency dependence of the AC electrical conductivity of different compositions of bismuth cuprate glasses has been presented in the temperature range 80-400 K. The conductivity data have been analysed in terms of different theoretical models to determine the possible conduction mechanism. Analysis of the conductivity data and the frequency exponent shows that the correlated barrier hopping of electrons between Cu+ and Cu2+ ions in the glasses is the most favourable mechanism for AC conduction. The different parameters obtained from the fits of this model to the experimental data are reasonable. The high value of the dielectric constant observed in this glass system can be attributed to the influence of the high polarizability of the Bi3+ ions of the unconventional network former Bi2O3 on the AC response.