Spin Relaxation and Transport in Magnetic Alloys

Abstract

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.