Correlation Functions in Nuclear Relaxation. I. Analysis of Random Motions from Field Dependence of Relaxation Times

摘要

The contributions toT1in a fluid arising from spinmdash;rotational interaction and chemicalhyphen;shielding anisotropy are discussed in terms of their simultaneous use to analyze the detailed nature of random rotations without the need of a microscopic theory. This possibility often exists because of the involvement of different correlation functions of the lattice variables and the experimental distinguishability of the latter mechanism through its magnetichyphen;field dependence. The method is illustrated by comparing the results to be expected for three different random processes: (1) rotational diffusion, (2) random walk among themjstates of a rotational manifold of fixedJwith no selection rules, (3) the same with a rigorous Dgr;mj=plusmn;1 selection rule. Possible favorable experimental cases are discussed.