Optical Properties of quaternary TeO2-ZnO-Nb2O5-Gd2O3 glasses

Quaternary tellurite glass systems in the form 75TeO(2)-15ZnO-(10-x)Nb2O5-xGd2O3, where (x=0.0, 0.5,1.0,1.5,2.0 and 2.5 mol%) have been prepared by the melt quenching technique. Optical absorption studies are carried out on the glass system in the wavelength range of 380-500 nm. The cut-off wavelength lambda(c), optical band gap E-opt, Urbach energy Delta E and refractive index n values were calculated from optical absorption data. Also, different physical parameters such as, molar refraction RM, metallization criterion M, electronic polarizability of the oxide ion alpha(2-)(o) (calculated from E-opt), and optical basicity Lambda have been determined. The FTIR absorption spectra for all glasses in the range of wave numbers 350-4000 cm(-1) has been recorded and designated. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).