11B MAS NMR spectroscopy for characterizing the structure of glasses

11B MAS NMR spectroscopy has been shown to deliver reliable parameters for the chemical shift and the quadrupole interaction in glasses if short excitation pulses, high-speed magic angle spinning and satellite transition spectroscopy are applied. It is possible, in particular, to separate the contributions for trigonal BO3 and tetrahedral BO4 units to determine the relative fractions of both, and to use the isotropic chemical shift values as a sensitive probe for the nearest and next nearest environments of the boron atoms. The potential of the method has been demonstrated for some borate and borosilicate glasses prepared by the alkoxide gel techniques.