Many-quantum transitions in conduction electron spin resonance

Resonance absorption spectra have been observed which may be interpreted as many-quantum transitions where the quantization is along the effective field in the rotating frame. The spin system used was that of the conduction electrons in Li metal in a crystal of neutron irradiated LiF. An analysis of the experimental results using a modified Bloch equation under the assumptions that [Formula: see text] and that the spin system relaxes towards the instantaneous field is presented. The agreement between theory and experiment is excellent.