Critical phenomena in canonical spin glass AuMn from Hall effect measurements

Abstract

The extraordinary Hall resistivity ρ ex and the magnetization M of canonical spin glass AuMn with 8 at% Mn were measured simultaneously as a function of temperature with close attention to thermal and magnetic field hysteresis. The data of ρ ex show an anomaly at the spin glass transition temperature T g . Moreover, the anomalous Hall coefficient R S ∼ ρ ex / M , which represents the chiral susceptibility of the system in the present case, also shows the anomaly. In conventional theories, the extraordinary Hall resistivity ρ ex is represented, ρ ex = M ( A ρ + B ρ 2 ) , where ρ is the resistivity, and A and B are constants. Since ρ ( T ) is monotonic and smooth, the behavior of ρ ex / M clearly indicates that another term has to be included in the expression of ρ ex . The results can be interpreted consistently in terms of a chirality ordering model of canonical spin glasses. We argue the critical phenomena of the spin glass transition from Hall effect measurements in comparison with that from magnetization measurements.