SPIN RELAXATION AND TRANSPORT IN MAGNETIC ALLOYS

The spin susceptibility for an interacting electron gas is derived, including a fully microscopic treatment of spin relaxation and transport effects due to nonmagnetic impurities. The corresponding macroscopic equations for the paramagnet resemble the relaxation-to-equilibrium phenomenological model, with the spin relaxation time given by the spin-orbital scattering rate appearing in the self-energy, multiplied by renormalization factors. In the ferromagnetic region, the spin diffusion constant is found to be much smaller than in previous estimates. The consequences for paramagnons are briefly discussed. © 1968 The American Physical Society.