Low-Field Magnetoresistance of Palladium Alloys

Observations are reported of a negative contribution to the magnetoresistance of a paramagnetic transition metal, palladium, with nonmagnetic impurities. The longitudinal magnetoresistance of some polycrystalline palladium alloys which show a resistance minimum is compared with the magnetoresistance of palladium alloys with no resistance minimum. Kondo scattering in these alloys cannot account for the results, but we suggest that the energy dependence of Mott $s-d$ scattering, used successfully to explain the temperature dependence of resistivity of these alloys, is also responsible for the negative magnetoresistance. A positive contribution to the magnetoresistance which, unlike the negative component, obeys Kohler's rule is also present. We attribute this component to anisotropy of scattering on the Fermi surface. It proves to be surprisingly sensitive to the impurity type, suggesting that this may be a profitable way to study the anisotropy of scattering in other paramagnetic transition metals.