Analysis of the Quadrupolar Coupling Effect on the Line Intensities Using Single-Crystal Nutation NMR in α-Al2O3 Crystals

With 1D-nutation NMR for a spin I = 5/2 system, the relative line intensities of the central and the innerand outer-satellite transitions are calculated as functions of quadrupolar coupling ωQ and rf pulse strength ωrf. Experimentally measured line intensities including both central and satellites are used to extract the values of ωQ and ωrf from nonlinear least-squares fits. The method is illustrated in α-Al2O3 crystals (ruby and corundum) with the single-crystal Al nutation NMR spectra. As a result, the new feature that the rf pulse strength shows reduced effect on the satellite transition lines according to the quadrupolar coupling is discussed by using a fictitious spin-1/2 operator.