Cross Relaxation in LiF

Abstract

A combined experimental and theoretical study of cross relaxation in LiF has been carried out. In agreement with theory, the cross-relaxation time ${T}_{21}$ is observed to be strongly anisotropic and field dependent; at 51.7 gauss it goes from 0.025 second in the [100] direction to 7 seconds in the [111] direction. A frequency distribution function analogous to the line shapes for magnetic absorption is measured down to ${10}^{\ensuremath{-}4}$ times the maximum value; for most orientations a Gaussian is an excellent approximation to it.