Glass formation and structure of calcium antimony phosphate glasses and those doped with tellurium oxide

An approximate glass-forming region in the P2O5–Sb2O3–CaO ternary system was determined. The properties and structure of two compositional series of (A) (75−x)P2O5–xSb2O3–25CaO (x = 20, 25, 30, 35 mol%) and (B) 45P2O5–30Sb2O3–(25−x)CaO–xTeO2 (x = 5, 10, 15, 20 mol%) were studied systematically. Thermal properties were investigated by means of differential scanning calorimetry (DSC). The densities of all samples were measured by Archimedes’ method using distilled water as the immersion liquid. The water durability of the glasses was described by their dissolution rate (DR) in the distilled water at 90 °C for some time periods. Density, thermal stability and water durability were improved with the addition of Sb2O3 and TeO2. Structural studies were carried out by X-ray diffraction (XRD), infrared spectroscopy and Raman spectroscopy. The phosphate chain depolymerization occurred with the increase of Sb2O3 and the Q2 structural units transformed to the Q1 and Q0 structural units with the addition of TeO2.