On the Screening of Magnetic Interaction by Degenerate Free Electrons

A detailed investigation was made on the self-consistent determination of the vector potential due to a magnetic point dipole imbedded in a medium of degenerate free electrons. The Thomas-Fermi method shows that the screening by an induced electric current is Landau-diamagnetic, and practically negligible. A dynamical method is then applied to the same problem to investgiate the effect of a flip motion of the point dipole on tbe screening. In this case another type of screening arises which is due to tbe inability of some electrons to follow the nonadiabatic change of force induced by the flip motion. The derived potential is used for the calcuiation of tbe spin-lattice relaxation time in ferromagnetic metals, and Kasuya' s estimation of its order of magnitude is proved to be reasonable. Some discussion is also given of its temperature dependence. (auth)