Nuclear Magnetic Resonance Line Shapes Resulting from the Combined Effects of Nuclear Quadrupole and Anisotropic Shift Interactions

Abstract

The effects on the nuclear magnetic resonance line shape of a polycrystalline sample resulting from combined axially symmetric electric quadrupole and anisotropic shift interactions have been calculated through the second order. The line shape of the central transition of the resonance has been shown to change smoothly from that characteristic of quadrupole effects (inverse field dependence) to that characteristic of anisotropic shift effects (direct field dependence) as the magnetic field strength is increased. Methods are given for determining the magnetic shift parameters—both isotropic and anisotropic (axial)—and the electric quadrupole coupling from line shape and shift measurements. An illustration of these methods is given, based on experimental measurements of the ${\mathrm{Al}}^{27}$ spectrum in polycrystalline Pr${\mathrm{Al}}_2$.