Abstract
New synthesis fluoro-tellurite in the form in [75TeO2–10ZnO–5LiF– (10−γ) Nb2O5–γNaF] where γ=0, 2, 4, 6, 8 and 10mol% 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 (350–4400cm−1) and the Raman spectroscopy in the range (40–4450cm−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 (298–923K).Optical absorption spectra were recorded in the range (190–2500nm). 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.
•Synthesis of new Fluoro-Tellurite (TeO2–ZnO–LiF–Nb2O5–NaF) glass system.•Formation of TeO3+1, TeO3 (or) Te (O, F)3+1units in Fluoro-Tellurite glasses.•The thermal stability of these glasses was relatively large (>100K).•Refractive index increased gradually to 2.546 with increasing NaF mol% content.