28 August 2022 to 2 September 2022
Science and Technology Campus, University of Parma
Europe/Rome timezone
The Open Access Conference Proceedings is Now Available!

The site and high field $\beta$NMR properties of $^8$Li$^+$ implanted into $\alpha$-Al$_2$O$_3$

P-MON-29
29 Aug 2022, 17:20
1h 40m
Science and Technology Campus, University of Parma

Science and Technology Campus, University of Parma

University of Parma, Italy
Poster Site calculations Posters

Speaker

Prof. Andrew MacFarlane (Chemistry Department, The University of British Columbia)

Description

We present high magnetic field $\beta$NMR measurements of $^8$Li$^+$ implanted in single crystals of sapphire, a commonly used backing material for other samples. From the well-resolved quadrupolar splitting, we extract the electric field gradient (EFG) at the implanted $^8$Li$^+$ site. Comparison with supercell density functional theory calculations of the EFG allows us to identify the octahedral interstitial site as the most likely candidate. In contrast to the zero field $\beta$NQR spectra, only a single site is evident at high field. We discuss possible explanations for this discrepancy. The high field spin lattice relaxation is extremely slow ($1/T_1 < 0.02$ s$^{-1}$) from 4 to 300 K. This regime, where cross relaxation to the $^{27}$Al nuclear spins is quenched, extends down to at least 2.2 Tesla.

Primary authors

Prof. Andrew MacFarlane (Chemistry Department, The University of British Columbia) Mr Zaher Salman (Laboratory for Muon Spin Spectroscopy, Paul-Scherrer-Institute, CH-5232 Villigen PSI, Switzerland) Dr J.K. Shenton (Scientific Computing Department, Science & Technology Facilities Council ) Dr Aris C. Chatzichristos (Physics Department, Khalifa University, United Arab Emirates) Dr David L. Cortie (Australian Nuclear Science and Technology Organisation) Martin Dehn (Department of Physics and Astronomy, University of British Columbia) Derek Fujimoto (TRIUMF) Victoria Karner (TRIUMF) Rob Kiefl (University of British Columbia) Dr Dimitrios Koumoulis (Center for Applied Energy Research, University of Kentucky) Dr C.D.P. Levy (TRIUMF) Mr Ryan M. L. McFadden (UBC) Iain McKenzie (TRIUMF) Dr Gerald D. Morris (TRIUMF) Dr M.R. Pearson (TRIUMF) Dr Monika Stachura (TRIUMF) John Ticknor (University of British Columbia)

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