Effect of P2O5 addition on the structural and spectroscopic properties of sodium

The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses (x=0 to 7 mol%) are investigated. Both Raman and IR spectra reveal that discrete phosphate species ([PO4]^{-3}, [PO3O_{1/2}]^{-2}) with low polymerization degree can be formed in the silicate glass. These phosphate structur