Oxygen sites in silicate glasses: a new view from oxygen-17 NMR

Nuclear Magnetic Resonance (NMR) studies of O-17 in silicate glasses is beg inning to provide new information on structure from an "anionic" viewpoint, which is an important complement to more traditional discussions of cation coordination and connectivities. A variety of techniques are discussed her e, but the most important recent advances have used the new, two-dimensiona l, high resolution techniques of Dynamic Angle Spinning (DAS) and Triple Qu antum Magic Angle Spinning (3QMAS), which have resolved and distinguished p eaks for bridging oxygens linking Si, Al and B cations, as well as non-brid ging oxygens. These approaches have provided some of the first quantitative constraints on the extent of ordering, both among network modifier cations and among network former cations. (C) 2001 Elsevier Science B.V. All right s reserved.