The magnetoresistance of gold-iron alloys in high fields

The resistance of Au-Fe alloys with Fe concentrations of 110, 300, 1100 and 1900 ppm has been measured in the temperature range 0.4-20 K in fields up to 77 kOe. Interaction effects are negligible for the two dilute alloys, but reduce the magnetoresistance of the others. The magnetoresistance of the dilute alloys is a universal function of H/T for temperatures above 2.5 K, but is reduced at lower temperatures. For high values of H/T the magnetoresistance increases roughly as lg H, as predicted by theory. However, the temperature dependence cannot be explained by simple theory. It appears that very large fields would be required to remove completely the anomalous magnetoresistance.