title: 71Ga Chemical Shielding and Quadrupole Coupling Tensors of the Garnet Y(3)Ga(5)O(12) from Single-Crystal (71)Ga NMR.
abstract: A single-crystal (71)Ga NMR study of the garnet Y(3)Ga(5)O(12) (YGG) has resulted in the determination of the first chemical shielding tensors reported for the (71)Ga quadrupole. The single-crystal spectra are analyzed in terms of the combined effect of quadrupole coupling and chemical shielding anisotropy (CSA). (71)Ga quadrupole coupling and CSA parameters for the two (tetrahedrally and octahedrally coordinated) gallium sites with axial symmetry in YGG (Ga(IV), C(Q) = 13.1 +/- 0.2 MHz and delta(sigma) = 54 +/- 50 ppm; Ga(VI), C(Q) = 4.10 +/- 0.06 MHz and delta(sigma) = 24 +/- 3 ppm) are fully consistent with its cubic crystal structure which supports the reliability of the experimental data. In addition, the (71)Ga and (27)Al isotropic chemical shifts for YGG and YAG give further support to the linear correlation observed earlier between (71)Ga and (27)Al isotropic chemical shifts.
authors.affiliation: Instrument Centre for Solid-State NMR Spectroscopy, Department of Chemistry, University of Aarhus, DK-8000 Aarhus C, Denmark, and Centre de Recherches sur la Physique des Hautes Températures, 1D Ave de la Recherche Scientifique, 45071 Orléans Cedex 2, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Vosegaard
authors.forename: Dominique
authors.initials: D
authors.lastname: Massiot
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gautier
authors.forename: Hans J.
authors.initials: HJ
authors.lastname: Jakobsen