8Li+ β-NMR in the Cubic Insulator MgO

[摘要] We present extensive high magnetic field β-NMR measurements of8Li+implanted in single crystals of MgO. The narrow resonance, consistent with a cubic8Li+site, likely the tetrahedral interstitital, is used routinely as a reference for shift measurements. We show the intrinsic linewidth is on the order of 200 Hz, allowing a frequency determination to an accuracy of a few Hz. We find no implantation energy dependence of the resonance within a few ppm, but there is evidence of slow spin dynamics in hole-burning measurements. The spin lattice relaxation is slow. The temperature dependence reveals interesting changes at low temperature whose origin remains uncertain.

[发布机构] Chemistry Department, University of British Columbia, Vancouver; BC; V6T 1Z1, Canada^1;Department of Physics and Astronomy, University of British Columbia, Vancouver; BC, Canada^2;Quantum Matter Institute, University of British Columbia, Vancouver; BC; V6T 1Z1, Canada^3;Department of Physics, University of Alberta, Edmonton; AB; T6G 2E1, Canada^4;TRIUMF, Vancouver; BC; V6T 2A3, Canada^5;Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, Villigen PSI; 5232, Switzerland^6

[关键词] Frequency determination;High magnetic fields;Implantation energies;Low temperatures;Narrow resonances;NMR measurements;Shift measurement;Temperature dependence