On the structural arrangement and optical band gap (PbO)x(ZnO)10(TeO2)90 − x glasses

The glasses (PbO)x(ZnO)10(TeO2)90 − x, where x = 10, 20, 30, 35 and 40 mol%, were prepared with a classic melting method from pure oxides. With an increase in x the density increases from 5.92 (x = 10) to 6.8 (x = 40) g/cm3, the glass-transition temperature decreases from 299 to 254 °C and the optical band gap decreases from 3.73 to 3.48 eV. It is suggested from the Raman scattering spectra that the structural units inherent to [Te3O8]4 − and [TeO3]2 − anions form the Te-O based network, that is with an increase in x the conversion proceeds from TeO4 to TeO3 structural units. The values of the non-linear refractive index were estimated from the optical band gap values in the region: (6.5-8.4) × 10− 12 esu.