Giant Thermo-Electric Power of Dilute Magnetic Alloys

Abstract

Because of a dynamical character of the s-d interaction the probability of the scattering of conduction electrons by magnetic impurities is found to involve a term proportional to 2/(E) -1, where /(E) is the fermi distribution function. Since df(c)/dc is large at the fermi surface, thermo-electric power arising from the diffusion of conduction electrons becomes very large. It is found to be independent of the temperature and the concentration of magnetic impurities at the paramagnetic region. As the temperature is reduced so that kT is comparable to or smaller than the Zeeman splittings of impurity spins, it decreases in magnitude and tends to zero linearly in the temperature. It also decreases when scattering due to phonon or non-magnetic impurities dominates over the magnetic scattering. A connection among low-temperature behaviors of resistivity, thermo-electric power and specific heat of dilute magnetic alloys is pointed out.