The role of intergrain junctions in transport critical current irreversibility

Abstract

The magnetic field dependence of voltage at constant measuring currents of YBa2Cu3O7−δ bulk ceramics and Bi(Pb)SrCaCuO screen printed films were studied at different temperatures so as to obtain information on critical current irreversibility. Two ranges of these curves were found to show sensitivity to magnetic field. They suggest that the two types of superconducting medium, i.e., the Josephson and Abrikosov medium, result in two different voltage generation mechanisms. It is shown that the Josephson medium plays a role in both low and high magnetic field critical current irreversibility.