Physical and Optical Properties of Lead-Tungsten-Tellurite Glasses

Abstract

By using the melt quenching approach, a number of tellurite-based heavy metal oxide glasses codoped with varied lead oxide (PbO), (80-x)TeO2-20%WO3-xPbO (x = 5, 10, 15 and 20 mol%) compositions, have been created. By using UV-Vis-IR spectroscopy, forbidden energy gap, Urbach energy, and refractive index were calculated and the contribution of PbO to the glasses structure was investigated. Calculations were also made for physical parameters such as density, molar mass, and oxygen packing density, polaron radius, inter-ionic distance, and molar refraction. The direct and indirect optical band gaps is 3.29 to 3.33 eV and 3.2 to 3.3 eV, respectively. The fact that the nonbridging oxygen ion content rises with increasing PbO content and shifts the band edge to lower frequencies, may be the cause of a drop in the values of the energy band gap Eg.