Nonexponential Nuclear Magnetic Relaxation by Quadrupole Interactions

Abstract

Results are presented of calculations showing that the nuclear magnetic relaxation of the longitudinal and transverse components of a spin I are different, but each is the sum of $I$ decaying exponential terms if $I$ is an integer, or the sum of $\mathrm{I\hspace{0.17em}+\hspace{0.17em}}\frac{1}{2}$ decaying exponential terms if $I$ is half an odd integer, if the relaxation is produced by quadrupole interactions for which the correlation time is not short compared to the Larmor period. Expressions for the exponents and coefficients are given in detail for the case $\mathrm{I\hspace{0.17em}=\hspace{0.17em}}\frac{3}{2}$ . If the correlation time is short, the expressions reduce to the simple exponential decays calculated by previous investigators.