Theory of paramagnetic resonance and relaxation of conduction electrons in quantizing magnetic fields

A theory of magnetic resonance for conduction electrons in quantizing magnetic fields is developed on the basis of Zubarev's nonequilibrium statistical operator method. Expressions are found for the relaxation times of the electron spin, these expressions depending on strength of the dc magnetic field and the frequency of the alternating magnetic field. It is shown that in the limit of weak magnetic fields the longitudinal and transverse relaxation times are equal to each other; in quantizing fields the transverse time is less than the longitudinal time and is strongly frequency dependent. A study is made of the effect of scattering on the shift of the temperature-dependent epr frequency. Estimates are given for the resonant growth of the mean kinetic energy of the electrons in the case of epr saturation.