Synthesis and optical properties of new fluoro-tellurite glass within (TeO2-ZnO-LiF-Nb2O5-NaF) system

New synthesis fluoro-tellurite in the form in [75TeO2-10ZnO-5LiF- (10 − γ) Nb2O5-γNaF] where γ = 0, 2, 4, 6, 8 and 10 mol% have been successfully synthesized by rapid melt-quenching technique. Also, the effect of doping the present prepared glasses by NaF on the optical properties has been discussed. Their densities were determined by Archimedes method. Values of the molar volume and the oxygen packing density were calculated. Both the Fourier-transform-infrared (FTIR) in the wavenumber range (350-4400 cm− 1) and the Raman spectroscopy in the range (40-4450 cm− 1) were used to prove the changes in the structure of the prepared glasses. The glass transition temperature (Tg), crystallization temperature (Tc) and melting temperature (Tm) were determined by using Differential Scanning Calorimetry (DSC) as a function of NaF (mol%) in the temperature range (298-923 K).Optical absorption spectra were recorded in the range (190-2500 nm). The indirect optical band gap (Eopt), Urbach energy (ΔE), refractive index (n), molar refraction (Rm), metallization criterion (M), electronic polarizability of the oxide ion (αo2) and the optical basicity (Λ) of the prepared glasses were calculated.