Temperature Dependence of Dielectric Conductivity of Borosilicate Glasses Modified by Iron Oxide

The temperature dependent conductivity of xFe2O3. (43-x) B2O3. 25SiO2. 30Na2O. 2Al2O3 glass system in the composition range of 1 - 12 mol% Fe2O3 was measured over temperature range from 40-400oC. The observed dependence follows simple Arrhenius relation as evidenced by the exponential variation of conductivity with temperature. The mechanism responsible for DC conductivity is primarily governed by the transport of sodium ions and electronic hopping of iron charge careers through the localized glass network. The electrical conductivity was found to be increased with raising temperature due to the thermal activation of the charge carriers. Both DC conductivity and activation energy values were significant effected by Fe2O3 addition- especially at higher content- which may be correlated with the variation in the two distinct conduction mechanisms present in the studied glass system.