Anisotropy dependence of anomalous Hall effect in canonical spin glass alloys

The influence of the Dzyaloshinsky-Moriya (DM) anisotropy on the extraordinary Hall coefficient , where ρ_ex is the extraordinary Hall resistivity and M is the magnetization, is investigated in canonical spin-glass (SG) alloys. The strength of the DM anisotropy in the alloys is changed systematically by doping with a third impurity that is non-magnetic. The Hall resistivity ρ_H, the magnetization M and the resistivity ρ were measured in the series of (Ag_1-xAu_x) _0.9Mn_0.1 alloys with x ≤ 0, 0.007, 0.03, and 0.05. The difference ΔR_s between the values of zero-field-cooled and field-cooled R_s, below the SG transition temperature, clearly increased with the amount of Au impurities. The dependence of the chirality contribution to R_s on the DM anisotropy is discussed in relation to the theoretical work for the chirality-driven anomalous Hall effect in the weak coupling regime.