Beta-detected NQR in zero field with a low energy beam of 8

Abstract

Beta-detected nuclear quadrupole resonances (β-NQR) at zero field are observed using a beam of low energy highly polarized radioactive 8 Li + . The resonances were detected in SrTiO3, Al2O3 and Sr2RuO4 single crystals by monitoring the beta-decay anisotropy as a function of a small audio frequency magnetic field. The resonances show clearly that 8 Li occupies one site with non-cubic symmetry in SrTiO3, two in Al2O3 and three sites in Sr2RuO4. The resonance amplitude and width are surprisingly large compared to the values expected from transitions between the | ± 2 ↔ | ± 1 spin states, indicating a significant mixing between the | ± m quadrupolar split levels.

Local Magnetic Properties of a Monolayer of Mn12 Single Molecule Magnets

“…The small ∆ 0 at high temperature in both samples is unrelated to the Mn 12 magnetic moments, but rather it is likely due to changes in the Si structure near the surface, caused by the grafted ligands and resulting in a small quadrupolar broadening. 24,40,41 As discussed above, a measurement of ∆ 0 , or more precisely the difference between the broadening in samples 1 and 2, as a function of temperature is equivalent to measuring the z component of the effective magnetic moment (m z ) of a single Mn 12 molecule. As shown in Figure 3, there is a sharp increase below ∼100 K and saturation at low temperature.…”

Near-Surface Structural Phase Transition ofSrTiO3Studied with Zero-Fieldβ-Detected Nuclear Spin Relaxation and Resonance

“…In addition, we obtain information on the orientation of the near-surface tetragonal domains below T c . More generally, since many other systems [9] produce an appropriate zero-field -NQR signal, we anticipate that the technique is applicable to a wide class of materials.…”

“…We are currently augmenting our β-NQR spectrometer with a high voltage platform [5] in order to enable such a depth-resolved study. We emphasize that the techniques described in this paper are not restricted to the study of SrTiO 3 , but should be applicable to investigations of structural phase transitions in many other materials where a nuclear quadrupole interaction is observed [9].…”

Determination of the nature of fluctuations using Li8 and Li9β -NMR and spin-lattice relaxation

“…It has been studied extensively with low-energy 8 Li β -NMR 31,32 . Implanted 8 Li occupies a single non-cubic site, which is unambiguously evidenced by the observation of a pure nuclear quadrupole resonance (NQR) in zero magnetic field [33][34][35][36] . Figure 4 shows the SLR spectra for 8 Li and 9 Li at 300 K at various magnetic fields between 0 mT to 15 mT applied along a (1 0 0) cubic crystallographic axis.…”

“…It has been studied extensively with low-energy 8 Li β -NMR 31,32 . Implanted 8 Li occupies a single non-cubic site, which is unambiguously evidenced by the observation of a pure nuclear quadrupole resonance (NQR) in zero magnetic field [33][34][35][36] .…”