Chiral susceptibility in canonical spin glass and reentrant alloys from Hall effect measurements

The extraordinary Hall effect coefficients $R_s(T)$ of the canonical spin glass alloys ${\bf Au}Fe 8 at\%$ and ${\bf Au}Mn 8 at\%$ and of an archetype reentrant system ${\bf Au}Fe 18 at\%$ 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 reentrant. The results can be interpreted consistently by invoking a chiral Hall effect contribution as proposed by Kawamura.