Nuclear Magnetization in the Presence of Ultrasonic Excitation

The field gradient at the site of a nucleus resulting from a relative displacement of surrounding charge is expanded in a Taylor series. The resulting expression is used to calculate the transition probability induced by this displacement for transitions of quadrupolar nuclei between $\Delta m=\pm 2$ spin levels in a sodium chloride-type lattice. The equilibrium nuclear magnetization in the presence of ultrasonic and thermal lattice vibrations is derived on the assumption of fast mutual spin-flip processes. The derivation is also based on a strain-free lattice.