LOW-FIELD NMR LINE-SHAPE DUE TO ANISOTROPIC LOCAL-FIELDS

The NMR line shape in a weak external field is investigated for the nuclear spin system with anisotropic distribution of the local magnetic fields by extending the Kubo-Toyabe model. It is shown that the line shape for a highly anisotropic system exhibits characteristic features and the peak position of the main line deviates considerably from the Larmor frequency of the applied field. A brief comment is also given on the line shape of the rotary resonance examined previously by Redfield, which may be useful to investigate the low-field NMR line shape.