NMR Studies of Bond Arrangements in Alkali Phosphate Glasses
Solid-state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy has become a powerful tool for the investigation of local structure and medium range order in glasses. Previous P-31 MAS NMR studies have detailed the local structure for a series of phosphate glasses. Phosphate tetrahedra within the glass network are commonly described using the Q(sup n) notation, where n = 0, 1, 2, 3 and represents the number of bridging oxygens attached to the phosphate. Using P-31 MAS NMR different phosphate environments are readily identified and quantified. In this paper, the authors present a brief description of recent one dimensional (1D) Li-6, Li-7 and P-31 MAS experiments along with two-dimensional (2D) P-31 exchange NMR experiments for a series of lithium ultraphosphate glasses. From the 2D exchange experiments the connectivities between different Q(sup n) phosphate tetrahedra were directly measured, while the 1D experiments provided a measure of the P-O-P bond angle distribution and lithium coordination number as a function of Li2O concentration.
R. K. Brow and T. M. Alam, "NMR Studies of Bond Arrangements in Alkali Phosphate Glasses," Proceedings of the 18th International Congress on Glass, Japan Aerospace Exploration Agency (JAXA), Jan 1998.
Materials Science and Engineering
Keywords and Phrases
Lithium Oxides; Solid State; Alkalies; Chemical bonds; Glass; Lithium - isotopes; Molecular structure; Nuclear magnetic resonance; Phosphates
Article - Conference proceedings
© 1998 Japan Aerospace Exploration Agency (JAXA), All rights reserved.