Thermal and optical characteristics of synthesized sand/CeO2 glasses: Experimental approach

Abstract

In this study, glass samples of composition 20PbO-20CaO-20Sand-(40 − x)B2O3-xCeO2, where x = 0, 2.5, 5, 7.5, and 10 in wt.% and sand = SiO2 (90.4%) + CaO (2.8%) + ZrO2 (2.3%) + Fe2O3 (2.1%), were fabricated via the ordinary melt quenching technique. The thermal and optical properties of the glasses were experimentally investigated using differential scanning calorimetry (DSC) analysis, which is measured as a function of temperature based on the difference in the amount of heat needed to raise the temperature of a sample and reference. All glasses were found to be thermally stable up to 550°C. The glass transition temperature (Tg) varied from 211°C to 219°C, crystallization temperature (Tc) varied from 303°C to 310°C, and melting point (Tm) was 577°C. The values of the indirect optical energy band gaps (EOptical, Indirect) reduced from 2.63 eV to 2.28 eV, while the direct gaps (EOptical, Direct) reduced from 5.07 eV to 4.17 eV. Urbach’s energy (EU) was changed from 0.42 eV to 0.46 eV. The dielectric constant behaved similarly to the refractive index and absorption coefficient of the proposed glasses. The refractive index data were analyzed to obtain important optical information and the corresponding derivative electrical parameters, namely, the oscillator energy, dispersion energy, dielectric constant at high frequency, the dielectric loss, and the energy-loss functions. There was a remarkable increase in the optical conductivity (σopt) with increasing CeO2 content, with peaks appearing in all samples doped by CeO2 and reaching a peak maxima of about 2.72–3.10 eV. Volume energy loss (VELF) and surface energy loss (SELF) functions were increased with increasing CeO2 content, with a characteristic peak at around 3.47 eV for all proposed samples. © 2022, The Minerals, Metals & Materials Society.