Spin–Glass-like Transition and Hall Resistivity of Y_2−xBi_xIr₂O₇

Abstract

Various physical properties of the pyrochlore oxide Y_2−xBi_xIr₂O₇ have been studied. The magnetizations M measured under the conditions of the zero-field-cooling (ZFC) and the field-cooling (FC) have different values below the temperature T=T_G. The anomalous T-dependence of the electrical resistivities ρ and the thermoelectric powers S observed at around T_G indicates that the behavior of the magnetization is due to the transition to the state with the spin freezing. In this spin-frozen state, the Hall resistivities ρ_H measured with the ZFC and FC conditions are found to have different values, too, in the low temperature phase (T<T_G). Possible mechanisms which induce such the hysteretic behavior are discussed.