B. Bureau et al., From crystalline to glassy gallium fluoride materials: an NMR study of Ga-69 and Ga-71 quadrupolar nuclei, SOL ST NUCL, 14(3-4), 1999, pp. 181-190
Owing to the implementation of acquisition techniques specific for nuclei w
ith very large quadrupolar interaction (full shifted echo acid variable off
set cumulative spectra (VOCS)), NMR spectra of Ga-69 and Ga-71 are obtained
in crystallised (PbGa5, Pb-3,Ga2F12, Pb9Ga2F24 and CsZnGaF6) and glassy (P
bF2-ZnF2-GaF3) gallium fluorides. Simulations of both static (full echo or
VOCS) and 15 kHz MAS spectra allow to obtain consistent determinations of i
sotropic chemical shifts and very large quadrupolar parameters (nu(Q) up to
14 MHz). In the crystalline compounds whose structures are unknown, the nu
mber and the local symmetry of the different gallium sites are tentatively
worked out. For the glassy systems, a continuous Czjzek's distribution of t
he NMR quadrupolar parameters accounts for the particular shape of the NMR
spectrum. (C) 1999 Elsevier Science B,V. All rights reserved.