Thermal expansion and structural properties of some (PbO)x(ZnO)35−x(TeO2)65 glasses

Abstract

AbstractThe glasses (PbO)x(ZnO)35−x(TeO2)65 with 0 < x < 25 were prepared by conventional melting method. The substitution of ZnO by PbO leads to a decrease in the glass transition temperature (Tg) from 338 to 280 °C and an increase in the linear coefficient of thermal expansion (α) from 15.8 to 19.2 ppm K−1. A correlation between α and Tg has been confirmed by the Lindemann rule. The two prediction methods of the coefficient of thermal expansion (α) were compared with experimental values: the simple additivity model and the Mackenzie method. From Raman spectra, it is evident that the substitution of ZnO by PbO leads mainly to the conversion of TeO4 structural units to TeO3 structural units. This conversion leads to network depolymerization.