Nuclear Magnetic Resonance Powder Patterns of the Second-Order Nuclear Quadrupole Interaction in Solids with Asymmetric Field Gradient

Abstract

Numerical calculations of the powder pattern of the central component shifted by the second-order nuclear quadrupole interaction in solids have been performed for various values of the asymmetry parameter, η. Shape functions have been obtained in units of (νQ2/6νL) (a—¾) for η=0.1, 0.2, ···, 1.0, at 0.1 intervals. Also, positions of special points such as infinities and steps of the shape function have been determined as functions of η. Effects of the dipolar broadening of the single-crystal resonance upon powder patterns have been estimated for the case of η=0.5. Influences of anisotropic magnetic shift were also discussed on powder patterns obtained experimentally. These relations are useful for simple and rapid determinations of η and νQ from the second-order powder pattern.