Influence of SrO on structural, optical and electrical properties of LiF-MgO-Bi2O3- SiO2 glasses for energy storage applications

Abstract

Lithium strontium magnesium bismuth silicate glasses having composition 40SiO2 - 20Bi2O3- 20LiF - (20 - x) MgO–xSrO (x = 0, 5, 10, 15, and 20 mole%) were prepared using melt quenching technique. The prepared samples were characterized using XRD and FTIR techniques. Physical, optical and electrical properties have been investigated in order to understand the mixed modifier effect of MgO and SrO on these glasses. It was found that the addition of strontium at the expense of magnesium increases the density while decreasing the molar volume of the prepared samples. The XRD patterns showed that replacing magnesium with strontium led to enhance the vitreous formation of the prepared samples. Absorbance spectra, energy band-gap and Urbach energy were measured and calculated and the present glass system shows indirectly allowed transitions. Broadband Dielectric Spectroscopy measurements were carried in the frequency range 0.1 Hz to 10 MHz using a high resolution alpha dielectric analyzer in a temperature range from 25 to 200 °C. It was found that the dielectric parameters are enhanced with the increase in MgO content at the expense of SrO and with increasing temperature. The conductivity of the glass shows no dc conductivity behavior except at high temperature and yet it is non-conducting glass. However, the data suggest that the prepared glasses are promising for energy storage glass applications.