Spin–Glass-like Transition and Hall Resistivity of Y2-xBixIr2O7

Various physical properties of the pyrochlore oxide Y 2- x Bi x Ir 2 O 7 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.

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