Nuclear double resonance: cross relaxation rates between two spin species

A rotating-frame nuclear-double-resonance experiment is reported in which the cross-relaxation rates between 7Li and 6Li in powdered lithium metal were measured. The theory developed my McArthur, Hahn, and Walstedt (MHW) is applied to these data and good agreement is obtained. We also apply this theory to other published experimental data (LiF by Lang and Moran and adamantane by Pines and Shattuck) and find good agreement. We conclude that the assumption of a Lorentzian correlation function, which forms the basis of the theory of MHW is generally valid.