Irreversibility inBa0.625K0.375BiO3

Abstract
An irreversibility line has been identified in bulk Ba0.625 K0.375 BiO3, which follows the relation 1-T/TcH2/3. According to the flux-creep model, the magnetic irreversibility is caused by thermally activated flux creep and is closely connected with the field-induced resistive broadening. However, previous resistivity measurements showed that the Ba0.625 K0.375 BiO3 system did not exhibit resistive transition broadening. Thus, an alternative explanation based on the Josephson-coupling model is suggested to interpret the irreversibility observed in Ba0.625 K0.375 BiO3.