Physical, Optical and FT-IR studies of Bismuth-Boro-tellurite Glasses containing BaO as modifier

The addition of glass modifier changes the properties of host glass network. The role of Ba²⁺ as glass modifier has been investigated using physical, UV-Visible and FT-IR studies on xBaO-(30-x)TeO₂-35Bi₂O₃ -35B₂O₃ ( where x = 5,10,15,20 and 25 mole% ) glasses. X-ray diffractograms of crushed glass samples were recorded at room temperature. The absence of sharp peaks in X-ray diffractograms confirms the amorphous nature of the glass samples. Density (ρ) of glass samples were estimated using Archimedes principle. Physical properties such as molar volume (V_M), oxygen packing density (OPD), optical basicity etc. were determined. The optical absorption spectra were recorded in the wave length range of 200–1000 nm at room temperature. From the optical absorption spectra indirect allowed optical band gap, Urbach energy, refractive index (n), dielectric constant (ɛ), reflection loss (R), molar refractivity (R_m) and metallization criteria values were evaluated. The refractive index values were decreasing while optical band gap values were increasing with increasing concentration of BaO. IR spectra were recorded in the spectral range 400 - 4000 cm^–1.