The glasses, of the form 50Na2O–xTiO2–(50-x)P2O5 (with x = 0, 5, 10, 15) were characterized by infra-red spectroscopy, 31P magic angle spinning nuclear magnetic resonance and 31P double-quantum magic angle spinning nuclear magnetic resonance. The former spectra showed that phosphate network depolymerization occurred when x increased. Infrared spectra indicated that Ti was incorporated as TiO6/2 units. double-quantum magic angle spinning nuclear magnetic resonance permitted the characterization of the Qn,ij phosphate units. Their chemical shifts, measured on double-quantum magic angle spinning nuclear magnetic resonance spectra, were used as constraints for the deconvolution of one-dimensional magic angle spinning nuclear magnetic resonance spectra. It indicated the formation of diphosphate units bonded to Na and Ti Q1,1(Na,Ti), even at the lowest x-value. A structural unit formed by the sequence –Q2,22(Na)–Q2,21(Na)–Q1,2(Na,Ti)–TiO6/2–Q1,1(Na,Ti)–Q1,1(Na,Ti)–TiO6/2 could be proposed. The increase of conductivity and glass transition temperature with x was deduced from this structural model.

Structure and Ionic Conductivity of Sodium Titanophosphate Glasses. L.Montagne, G.Palavit, A.Shaim, M.Et-Tabirou, P.Hartmann, C.Jäger: Journal of Non-Crystalline Solids, 2001, 293-295, 719-25