Optical, physical and structural studies of boro-zinc tellurite glasses

To investigate the modification effect of the modifier ZnO on boro-tellurite glass, a series of glasses with compositions 50B(2)O(3)-(50-x)ZnO-xTeO(2) have been prepared by conventional melt quenching technique. Amorphous nature of the samples was confirmed through X-ray diffraction technique. Optical absorption and IR structural studies are carried out on the glass system. The optical absorption studies revealed that the cutoff wavelength increases while optical band gap (E-opt) and Urbach energy decreases with an increase of ZnO content. Refractive index evaluated from E-opt was found to increase with an increase of ZnO content. The compositional dependence of different physical parameters such as density, molar volume, oxygen packing density, optical basicity, have been analyzed and discussed. The IR studies showed that the structure of glass consists of TeO4, TeO3/TeO3+1, BO3, BO4 and ZnO4 units. (C) 2011 Elsevier B.V. All rights reserved.