Structure of Phosphorus Oxynitride Glasses

The structures of phosphourus oxynitride glasses have been determined using a combination of solid-state ³¹P, ¹⁵N, and ²³Na nuclear magnetic resonance and Raman spectroscopies. Raman spectra of model phosphazene compounds with different types of P–N bonding have been used to confirm spectral assignments. Results indicate that nitrogen replaces oxygen in the phosphrus atoms (via one double bond and one single bond) and as nitrogen bonded to three phosphorus atoms via three single bonds. The observed structural features are consistent with data which show that nitrogen influences the chemical durability, thermal expansion, and other properties of phosphate glasses by cross-linking ploymeric phosphate chain to gether in the glass network.