Contribution of collective excitations into magnetic relaxation

The present paper discusses the contributions from the collective excitations of an electron gas in a solid to the processes of spin relaxation of paramagnetic impurities. The calculations are presented of the times of relaxation caused by the interaction between plasma oscillations and a magnetic impurity, both with and without consideration of quantization of the orbital motion of conduction electrons. The presence of the spin-orbital interaction between the electrons and the lattice skeleton gives rise to the appearance of a new branch of collective excitations with the frequency ω Δgsub(s)ωsub(p), where ωsub(p) is the plasma oscillation frequency and Δgsub(s) is the spin part of the electron g-factor shift. The contribution from this branch of collective excitations to the relaxation times turns out to be the largest and of the same order of magnitude as Tsub(i), which is due to the single-particle exchange scattering of conduction electrons from the impurities