Effect of MgO on structural, thermal and conducting properties of V2-Mg O5- (x = 0.05–0.30) systems

Abstract MgO containing vanadate glasses of composition V2-xMgxO5-δ (x = 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) have been prepared successfully by melt-quench technique. The structural properties of the as-quenched samples are explored with the help of X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Thermal properties and conductivity of the samples are investigated using differential thermal analysis (DTA) and impedance spectroscopy, respectively. Density, inter-ionic distance, and fragility index are found to decrease with the addition of MgO content. Higher content of MgO improves the glass formation tendency and reduces the thermal stability of the samples. The conductivity of the V2-xMgxO5-δ samples decreases as the MgO concentration increases due to hindrance in the polaronic conduction of vanadium ions. The conductivity of the samples decreases to 10−4 S m−1 for x = 0.30 at 300 °C, while activation energy increases to 0.38 eV. These samples may find application in solid state batteries and fuel cells due to their higher conductivity.