Bismuth modified physical and optical properties of barium boro-tellurite glasses

Abstract

A quaternary glass system with compositions TeO2-Bi2O3-B2O3-BaO has been prepared by melt-quench method. The calculated values of density, molar volume and crystalline volume were found to increase with bismuth content. The absorption edge shifts towards lower wavelength side for all the compositions except x = 20 mol%. The optical band gap energy has been evaluated from extrapolation of Tauc’s plot results and Urbach energy has been estimated from linear fitting. The other optical parameters such as refractive index, molar refractivity and metallization criterion have also been discussed.