Optical and Electrical Properties of Sodiumborate Glass Containing V2O5

Glass system of the composition (Na2B4O7)100-x (V2O5)x, with x=0, 5, 7.5, 10, 12.5, 15 and 20 mol% has been prepared by conventional melt-quenching technique. The optical absorption and A.c conductivity have been measured. The optical absorption reveals that the electronic transition is indirect. The exponential dependence of the absorption coefficient α (α ≅ 103-104 cm-1) as a function of the incident photon energy (hυ) suggests that the urbach role is obeyed. A.C conductivity measurements are performed in the frequency range (0.1-100 KHz), over the temperature range (300-600K).Analysis of data suggests that correlated barrier hopping (C.B.H) is the dominant conduction mechanism. The dependence of dielectric constant (ε) and dielectric loss (tanδ) on both temperature and frequency are also discussed