Early 8 Li + β NMR investigations in GaAs and Ge
ABSTRACT In this paper, we describe initial studies of the structure and dynamics associated with Li+8 in bulk crystalline GaAs and Ge. At low temperatures in GaAs, the amplitude of the Li+8 resonance signal at ≈3T indicates that a large fraction (at least 70%) of the Li end up in locations with cubic symmetry (i.e. the tetrahedral interstitial and substitutional sites). The linewidth of the β-NMR Li+8 resonance increases dramatically above 150K, reaches a maximum at about 290K, and decreases again. This suggests that the Li starts to change its location, probably from an interstitial to a substitutional site, at ≈150K. Experiments in Ge are also described. In this sample, a narrow resonance is seen at low temperatures that is likely due to Li located at an interstitial site. Near room temperature, it appears that Li is converting to another site.
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ABSTRACT: Low-energy β-detected nuclear magnetic resonance was used to investigate the spatial dependence of the hyperfine magnetic fields induced by Fe in the nonmagnetic Ag of an Au(40 Å)/Ag(200 Å)/Fe(140 Å) (001) magnetic multilayer grown on GaAs. The resonance line shape in the Ag layer shows dramatic broadening compared to that of intrinsic Ag. This broadening is attributed to large magnetic fields induced in this layer by the magnetic Fe layer. We find that the induced hyperfine field in the Ag follows a power law decay away from the Ag/Fe interface with power −1.93(8), and a field extrapolated to 0.23(5) T at the interface.Physical review. B, Condensed matter 04/2008; 77(14). · 3.66 Impact Factor
- Physics Procedia 01/2012; 30:227-230.
- Physics Procedia 01/2012; 30:174-177.