Optical and electrical properties of PbO-TiO2, PbO-TeO2, and PbO-CdO glass systems

The optical and electrical properties of the lead bearing glasses in the PbO-TiO2, PbO-TeO2, and PbO-CdO systems have been investigated. The density, refractive index, optical band-gap, and Urbach energies of these glasses are reported. It is shown that the additive nature of oxide ion polarizabilities reported for the simple oxides can be extended to glass systems as well. A modified linear relationship between (E-opt)(1/2) and 1-(R-m/V-m) holds good for glasses. The oxide ion polarizabilities deduced from two different experimental quantities viz., refractive index and optical band-gap energy agree well. The de electrical conductivities have been measured in the temperature range 350-700 K. The activation energies are close to 1 eV. The low melting 70PbO-30TeO(2) glass shows higher isothermal conductivity compared to other glasses of similar composition. In PbO-TiO2 glass the PbO content contributes significantly to conductivity and composition dependence of pre-exponential factor (sigma(0)) supports tunneling mechanism. (C) 1997 American Institute of Physics.