Optical and kinetics parameters of lithium boro-tellurite glasses

Ternary lithium boro-tellurite systems in the form 75TeO2−xB2O3-(25−x) Li2O and 80TeO2-xB2O3-(20−x) Li2O where, x= 5, 10 and 15 mol% have been prepared by the melt quenching technique. UV- spectra of the prepared glasses in the range 200-550 nm has been recorded at room temperature. The cut-off wavelength (νc), optical band gap (Eopt) and Urbach energy (∆E) were calculated from optical absorption data. Differential scanning calorimetry (DSC) has been carried out on the prepared glass systems in the temperature range 400-800 K. The glass transition Tg and crystallization Tc temperatures values were measured from DSC thermo-gram. Activation energy for transition Et, activation energy for crystallization Ec and order of crystallization have been calculated for every glass composition.