THE EFFECT OF MAGNETIC-ANISOTROPY ON THE LONGITUDINAL NUCLEAR-RELAXATION TIME IN PARAMAGNETIC SYSTEMS

Calculated nuclear relaxation rates in paramagnetic systems with S = 1 2 are compared for the cases of fast and slow molecular tumbling. It is shown that the two treatments provide the same values before and after the low-field ωSτC = 1 dispersion, but differ in the dispersion region. Then the case of S = 1 2 is considered in order to check whether it could be treated with a fictitious S = 1 2 spin and large g anisotropy. Comparison is made with the approach which considers zero-field splitting explicitly. It is concluded that the latter approach is the more correct one. The applications are aimed at high-spin cobalt (II) systems. In order to facilitate comparison and future use, the relevant equations given in previous articles are presented in a simplified form and a common notation. © 1990.