Nuclear magnetic resonance (NMR) studies of the local structure of phosphorus chalcogenide glasses: an overview

An overview is given on recent nuclear magnetic resonance (NMR) structural studies of phosphorus chalcogenide glasses and melts. The detailed structur al speciation of these systems has been derived on the basis of P-31 dipola r spin-echo decay spectroscopy, magic-angle spinning (MAS), and variable te mperature liquid-state NMR above the glass transition temperature. A specif ic feature in the binary phosphorus/chalcogen systems is the competition be tween homo- and heteropolar bond formation, which can be quantitatively des cribed by means of these complementary NMR approaches. The effect of variou s elemental glass constituents upon these equilibria has been studied in a variety of ternary systems. Finally, MAS in combination with double-quantum (DQ) NMR provides detailed quantitative information on the network structu ral features present in ionically conducting thiophosphate glasses. (C) 199 9 Elsevier Science B.V. All rights reserved.