A MAS NMR structural study of cadmium phosphate glasses

Cadmium phosphate glasses, of general formula xCdO(1−x)P2O5 (0.25⩽x⩽0.6), have been prepared by melting in alumina crucibles, with resulting dissolution of up to 6.4 mol% Al2O3. The local structure in these glasses has been studied using 31P, 27Al and 113Cd nuclear magnetic resonance. The distribution of [PO4]Qn species as a function of composition has been shown to follow the simple binary model. The rate of change of the chemical shift of the 31P species in the Q2 environment depends on the bond order, which in turn reflects the extent of double bonding between phosphorus and oxygen.