Chiral susceptibility in canonical spin glass and re-entrant alloys from Hall effect measurements

The extraordinary Hall effect coefficients $R_s(T)$ of the canonical spin glass alloys $\mathbf{Au}Fe~8\tx{at}\%$ and $\mathbf{Au}Mn~8\tx{at}\%$ and of an archetype re-entrant system $\mathbf{Au}Fe~18\tx{at}\%$ were measured as functions of temperature. The data show a critical cusp-like term superimposed on a smooth background for the spin glasses, and change of sign with temperature for the re-entrant. The results can be interpreted consistently by invoking a chiral Hall effect contribution as proposed by Kawamura.