Influence of TeO2 on the UV, electrical and structural studies of Li2O–ZnO– B2O3 glasses

Abstract

Glass system of chemical composition xTeO2-(30-x)Li2O–20ZnO–50B2O3 with x = 0, 5, 10,15 and 20 mol% was fabricated through melt quench technique and investigated by X-ray diffraction technique, UV-Absorption spectroscopy, AC conductivity studies, FT-IR and Raman spectroscopy. No crystalline peaks were found in the XRD spectra which confirmed the amorphous nature of the glassy samples. The effect of conditional glass former TeO2 on the physical parameters like density, oxygen packing density (OPD) and molar volume have been investigated. The density of the glass system increased from 2.88 g/cm3 to 3.46 g/cm3 with the increase of TeO2 content. Optical absorption spectroscopic studies were carried out on the glass system. The Cut-off wave length (λc) varied between 300 nm and 370 nm whereas, the optical band gaps (Eopt) decreased with the addition of TeO2 in the glass network. The Urbach energy (ΔE) and refractive index of the glass system also increased. The AC conductivity measurements were studied up to high frequency (35 MHz) at various temperatures and conductivity observed in the higher order (10−2 Ω−1cm−1). Cole-Cole impedance plots shown semicircle behaviour in which the radius of semicircle decreased with increasing the temperature. Mechanical properties of the glass system were calculated using Makishima-Mackenzie model and the Poisson’s ratio values (0.17–0.21) are suggesting that the glass network has high cross link density. The Fourier Transform Infrared (FT-IR) and Raman spectroscopic studies revealed that the glass consisted of BO3 and BO4 units along with TeO3, TeO4 units.