A 29Si MAS NMR study of silicate glasses with a high lithium content

A series of lithium silicate glasses approaching the orthosilicate composition (66.7 mol% Li2O) were prepared and their 29Si magic angle spinning nuclear magnetic resonance (NMR) recorded; this significantly extends the compositional range of glasses studied by this technique. The results indicate that the lever (binary) rule is approximately followed, though with considerable dissociation of the stoichiometric groups into silicate units with lesser and greater numbers of non-bridging oxygens according to the relation . The NMR results were compared with the Raman study of Umesaki et al (1988 J. Non-Cryst. Solids 106 77–80) on the same system. Volumes per mol silica, determined from the experimental densities, were also used to test the structural results from the present NMR observations.