AC conductivity and dielectric relaxation in V2O5–P2O5–B2O3 glasses

Abstract

We investigated the AC conductivity in 60V2O5–(40 − x)P2O5–xB2O3 (x = 5, 10, 20, 30 and 35 mol%) glasses as a function of temperature. The measurements were carried out in the frequency range from 20 Hz to 1 MHz with varying temperatures (303–473 K). The samples were characterized by using X-ray diffraction (XRD) and thermogravimetric-differential thermal analysis (TG-DTA) techniques. The molar volume increases monotonically with the decrease in density. The AC conductivity increases with B2O3 content and temperature. The AC conductivity exhibited a Jonscher's universal power law and it is observed that as the temperature increases, frequency exponent (s) decreases. The dielectric constant of the sample decreases with increasing frequency and increases with temperature and concentration of B2O3. The electric modulus representation has been used to provide comparative analysis of the ion transport properties in these glasses. Scaling by using electric modulus shows overlap on single master curve signifying that the conduction mechanism is independent of temperature.

Keywords

• Dielectric loss
• Glass transition
• Thermal analysis
• Electrical conductivity