High Glass Transition Temperature Barium Silicophosphate Glasses Designed with Topological Constraint Theory

Alkali-free glasses have attracted tremendous attentions for their high glass transition temperature (T-g). Such a feature broadens their potential applications, especially in the area of high-density and high-power laser glasses. BaO-P2O5 glasses, as one of the major matrix materials due to its high-T-g, can be applied in high-power laser glasses. Introducing SiO2 is an effective method to improve the thermal, refractive index, and mechanical properties of phosphate glasses. Herein, we studied the barium silicophosphate glasses with MAS NMR and the T-g was successfully calculated by the topological constraint theory. The designed glass (20BaO-26.7SiO(2)-53.3P(2)O(5), mol%) with a high T-g (789K) was prepared and it also exhibited high refractive index and high Vickers hardness, suggesting the barium silicophosphate glasses have widespread applications in high-power laser glasses and optical fibers.