Cadmium invert sodium phosphate glasses: A structural peculiarities

xCdO.(100-x) (yNa2O.zP2O5) invert glasses, with CdO substituted for both Na2O and P2O5 were successfully prepared using a melt-quenching method. x changed up to 45 mol% and z equals y in all cases. 31P NMR studies show that CdO replaces both Na2O and P2O5, the total concentration of nonbridging oxygen atoms (NBO) increases. CdO switched its role of network intermediate to moodier with decreasing Na2O and P2O5 content Increasing NBO in the phosphate network causes a gradual decrease in density and increase in the molar volume of the glasses. Increasing CdO at expense of Na2O and P2O5 leads to the creation of more open spaces which can play the role of weakening in the structure that can be reflected by the increase of glass-free volume. Analysis based on NMR and FTIR spectroscopies confirmed that the Q2/Q1 ratio hardly decreased with increasing CdO at expense of equal concentration from P2O5 and Na2O.