Negative Transverse Magnetoresistance in Dilute Polycrystalline Alloys ofAuFe

The field dependence of the negative transverse magnetoresistance has been evaluated from the total effect measured in polycrystalline wires of the $\mathrm{Au}\mathrm{Fe}$ system at 2 and 4.2°K. The solute concentration ranged from 10-400 atomic ppm, and the applied field strengths ranged up to 26 kOe. In making this evaluation, consideration was given to the high-field-low-field transition, the anomalous size effects, the field dependence of the electron's relaxation time, and possible changes in the anisotropy of the solute scattering—considerations which will be relevant to similar measurements carried out on dilute alloys of analogous Kondo systems. For sufficiently concentrated samples, the negative component is shown to vary linearly with the square of the effective magnetization obtained from other work.