Anomalous behavior of the critical current of a grain-boundary Josephson junction in a bulk (Ba,K)BiO3 bicrystal
Roshchin I. V., Stepankin V. N., Yakovets Yu. P., Baranov M. A., Kuznetsov A. V., Zhigunov D. I., Shiryaev S. V.
The electrical transport properties of grain boundaries in bulk bicrystals of the oxide superconductor Bao 55K0 45Bi03 have been studied. The grain boundary in these bicrystals is a Josephson barrier. Near the transition temperature, the critical current of this barrier has a power-law temperature dependence with a critical exponent of 3/2. The critical current of a grain boundary exhibits a nonmonotonic behavior as the temperature is lowered. A possible interpretation of this behavior is discussed.