Advances in nuclear quadrupole resonance (NQR) spectroscopy have suggested the possibility one may be able to determine whether borate glasses contain the structural groupings (boroxyl, diborate, metaborate, etc.) that are found in the crystalline compounds of the borate systems. A new regenerative NQR spectrometer yields boron signals of about 100 at 1 MHz and permits measurements down to 200 kHz. The new NQR results allow the quadrupole coupling and asymmetry parameters to be determined to better than 1%, more than an order of magnitude better than from NMR spectra. NQR spectroscopy is yielding highly accurate values of these parameters in crystals and glasses, which should permit a positive identification of the structural groupings in borate binary glasses. Extensions to terniary glass systems are also planned. There are also plans to extend the work to aluminum nuclei to accurately determine the electric field gradient tensors at the aluminum site to ascertain the symmetry, coordination, and chemical bonding of the aluminum.
