STRUCTURE AND CHEMICAL MODIFICATION IN OXIDE GLASSES

The structure of oxide glass consists of relatively well defined oxide polyhedra, with significant disorder in the linkages between these gr oups. We review recent progress in understanding these structures, inc luding the length scales over which they exist, and how they may be mo dified chemically. We discuss two primary experimental methods: nuclea r magnetic resonance (NMR) spectroscopy and neutron diffraction. We ex plain how several methods for achieving high resolution in solid-state NMR may be applied to glasses, and how the data from NMR and neutron diffraction may be used together to generate large models that are con sistent with both sets. Specific examples are used to illustrate these points, including glasses based on berates? phosphates and tellurites .