The Site and High Field βNMR Properties of ⁸Li⁺ Implanted in α-Al₂O₃

Abstract We present high (> 2 T) magnetic field β NMR measurements of 8 Li + implanted in single crystals sapphire, a commonly used backing material for other samples. From the well-resolved quadrupolar splitting, we extract electric gradient (EFG) at site. Comparison with supercell density functional theory calculations EFG allows us to identify octahedral interstitial site as most likely candidate. In contrast zero NQR spectra, where multiple singals are detected, only is evident field. discuss possible explanations this discrepancy. The spin lattice relaxation extremely slow (1/ T 1 < 0.02 s −1 ) over broad temperature range from 4 300 K, demonstrating that cross 27 Al nuclear spins quenched such fields.