Quadrupolar spin-lattice relaxation in solids

Abstract

Calculations have been carried out for quadrupolar spin-lattice relaxation in NMR experiments, involving nuclei in non-cubic environments, which extend and, in certain cases, correct previous treatments for I=3/2, 5/2, 7/2 and 9/2. In particular, pulsed NMR experiments are treated and the results are presented in a way which reveals non-exponential effects. Since it is not in general meaningful to introduce a spin-lattice relaxation time some emphasis is placed on possible methods for measuring the quantities W2 and W1 which are related to the transition rates for Delta m=+or-2 and Delta m=+or-1 transitions involved in two-phonon relaxation processes. Results for 59Co in K3Co(CN)6 are briefly discussed.