Structure and properties of zinc aluminophosphate glasses and those doped with zirconium dioxide

• We investigate structure and properties of glass system ZnO–Al2O3–P2O5.
• In addition, a new glass system ZnO–Al2O3–P2O5–ZrO2 was also in research.
• Doping either Al2O3 or ZrO2 will enhance network density.
• Al2O3 and ZrO2 will also improve chemical durability of phosphate glasses.

Structure and properties of two glass systems, group A: 50P2O5–(50 − x)ZnO–xAl2O3 (x = 0, 5, 10, 15, 20 mol%) and group B: 50P2O5–20Al2O3–(30 − x)ZnO–xZrO2 (x = 1, 2, 3, 4, 5 mol%) were investigated. The density of the first series goes down with introducing more Al2O3, while the density increases as ZrO2 replaces ZnO in networks. Adding Al2O3 or doping more ZrO2 would raise Tg as well as Tc for both series of glasses. Adding Al2O3 does improve the chemical durability when comparing A1 with other members in the same group; further, doping ZrO2 into glasses based on A5 also makes some promotion in chemical properties. Structure analyses all coming from IR tests, it turns out that ion electronegativity does play an essential role in phosphate network when different kinds of ion exchange occur in glasses.