Magnetic field dependence of critical currents of single grain boundary junctions in y1ba2cu3o7-8 superconductor

The magnetic field dependence of the critical current of single YiBa2Cu307-8 grain boundary junctions has been measured as a function of temperature and orientation. A significant residual critical current is observed which increases with decreasing angle of misorientation at a given field and temperature. The data are in qualitative accord with a model in which the grain boundary comprises of a large number of micro-bridges in parallel. © 1993 IEEE