Magnetic field dependence of resistivity minima in amorphous LaGdAu alloys with high Gd content

Magnetoresistivity measurements have been performed in fields up to 40 kOe on some concentrated amorphous LaGdAu alloys exhibiting characteristics of a spin-glass. The negative magnetoresistivity at low temperature is found to be roughly proportional to the square of the magnetization. The resistivity minima in these alloys are attributed to a mechanism of electron scattering from magnetic clouds coupled by RKKY interactions, in qualitative agreement with analysis of our remanent magnetization data.