Spontaneous exchange bias effect in polycrystalline Bi 0.5 Sr 0.5 Fe 0.5 Cr 0.5 O 3

Bulk Bi 0.5 Sr 0.5 Fe 0.5 Cr 0.5 O 3 is a new compound comprising the R3c structure. The structural, magnetic, and exchange bias details are investigated. The material was in the paramagnetic state at room temperature. The field cooling H FC acts on the sample resulting in the exchange bias H EB . And the material is in a spontaneous polarization state, the exchange bias usually occurs at the boundary between ferromagnetic and antiferromagnetic states. The result shows that changing H FC from 1T to 6T reduces the H EB value by 16% at 2 K. Meanwhile, H EB diminishes as the ferromagnetic layer thickens. The variation of t FM with the change of H FC leads to the tuning of H EB by H FC in bulk Bi 0.5 Sr 0.5 Fe 0.5 Cr 0.5 O 3 . These effects are obviously different from the phenomenon seen in other oxide types.