Effect of intermediate oxide (Y2O3) on thermal, structural and optical properties of lithium borosilicate glasses

Glass and glass ceramic samples with composition 55SiO(2)-30B(2)O(3)-(x)Li2O-(15-x)Y2O3, where x = 0, 5, 10, 15 are prepared by conventional melt-quench technique. The structural, physical, thermal, optical, mechanical and conducting properties of these glasses are studied using X-ray diffraction (XRD), Differential Thermal Analyzer (DTA), Fourier Transform Infrared spectroscopy (FTIR), UV-visible spectroscopy and Impedance spectroscopy. Theoretical elastic moduli are calculated for the better understanding of the glass network strength. All samples, except with x = 0 glass, are amorphous in nature. Two broad halos are observed in x = 5 and x = 10 glasses, indicating phase separation in these glasses. Optical band gap of the samples decreases with increasing Y2O3 content. The lowest band gap is observed similar to 3.60 eV for x = 15 glass. Urbach energy increased with an increase in Y2O3 concentration. Y2O3 played different roles at different concentrations and enhanced the phase separation tendency in glass. The typical conductivity was observed similar to 10(-6) S/cm at 620 degrees C for x = 10 glass. (C) 2015 Elsevier B.V. All rights reserved.