Structure and properties of TeO2 and GeO2 containing phosphate and borophosphate glasses

Abstract

The glasses of various compositions in ternary system Li2O-P2O5-GeO2 and quaternary systems Li2O-B2O3-P2O5-TeO2, CaO-B2O3-P2O5-TeO2, Ag2O-B2O3-P2O5-TeO2, Li2O-B2O3-P2O5-GeO2 were synthesised and studied in 7 compositional series. The basic physicochemical properties of the glasses (density, molar volume, chemical durability etc.) were investigated using different analytical methods. The structure of glasses was studied using 31P, 11B MAS NMR and Raman spectroscopy. Thermal behaviour of glasses was investigated with the differential scanning calorimetry, thermodilatometry and hot-stage microscopy. From obtained thermoanalytical curves the values of glass transition temperature, dilatation softening temperature, crystallisation temperature and thermal expansion coefficient were obtained. DSC method was used also for the study of nucleation rate and nucleation (crystallisation) mechanism of the glasses. Crystalline phases obtained by annealing of glasses were identified by X-ray diffraction analysis.