Nuclear magnetic resonance studies in single-crystal tin specimens have been done at liquid helium temperatures. The Knight shift has been studied as a function of crystal orientation in a constant magnetic field for different values of field and temperature. The anisotropy of the Knight shift has been observed directly for the first time. The linewidth of the resonance has also been studied and the results indicate a contribution to this from indirect exchange interactions. An attempt has been made to observe oscillations in the Knight shift as a function of magnetic field in both tin and aluminum single crystals. None have been detected but an upper limit to the effect has been set and this is compared with theoretical estimates.
Monte Carlo simulation on the indirect exchange interactions of Co-doped ZnO film