Synthesis and Characterization of Lithium Borate Glasses Containing La2O3

The glass series with general formula 15 Li2O-(85 - x) B2O3-x La2O3 was prepared. Electrical and optical properties of these glasses were studied. It is observed that the conductivity of these glasses decreases while density, glass transition temperature and refractive index increases with the addition of La2O3. Ion concentration of La3+ in glasses, polaron radius, field strength, molar refractivity and molar electronic polarizability were calculated. The absorption coefficient and direct optical band gaps are evaluated using the absorption edge calculations. The different factors that play a role for controlling the refractive indices such as electronic polarizability, field strength of cations and rigidity of glass structure are discussed in accordance with the obtained index data.