Magnetoresistance of amorphous d-band metals with high electrical resistivity

Electrical resistivity and magnetoresistivity in amorphous Y₇₅Al₂₅ and Zr₄₀Cu₆₀ alloys have been measured from 0.5 to 20 K and in magnetic fields up to 85 kOe. The low temperature resistivity follows a square-root variation with temperature below 4 K in Y₇₅Al₂₅ and 10 K in Zr₄₀Cu₆₀. Using the measured values of the diffusion constant, the weak localization theory of magnetoresistance (incorporating both Zeeman splitting and spin-orbit interaction) predicts values which are lower (up to a factor of ∼ 3) than the experimental values (corrected for the Maki-Thompson and orbital-interaction contributions) in these high-resistivity alloys. The discrepancy cannot be explained by the spin-splitting interaction effect.