CRYSTAL-STRUCTURE STUDIES BY SINGLE-CRYSTAL NMR-SPECTROSCOPY - GA-71 AND GA-69 SINGLE-CRYSTAL NMR OF BETA-GA(2)0(3) TWINS

Ga-71 and Ga-69 single-crystal MMR spectra of a beta-Ga2O3 twin have b een analyzed in terms of the Ga-71/Ga-69 quadrupole coupling and chemi cal shielding anisotropy (CSA) interactions. Analyses of the magnitude s and orientations of the interaction tensors for the two distinct cry stallographic gallium sites in the two twin crystals resulted in accur ate values for the parameters describing the quadrupole coupling and C SA tensors. Moreover, it has been possible to determine the actual twi n-law of our sample crystal. Along with a recent Ga-71 Single-crystal NMR investigation of YGG, this work shows that gallium CSA generally h as to be taken into account in addition to the dominant quadrupole cou pling interaction.