Superconducting transport properties of YBa2Cu3O7- deltagrain boundary junctions

Abstract
The authors have studied the weak link properties of individual grain boundaries in thin film bicrystals of Y Y/Ba2Cu3O7 - delta . The grain boundary junctions (GBJs) show current voltage characteristics that can be closely modeled by the resistively shunted junction (RSJ) model. The magnetic field dependence of their critical current is Fraunhofer pattern like. Their Jc rho N products, where Jc is the critical current density of the GBJs and rho N their normal resistance times unit area, range between 0.2 and 8 mV and scale proportional to about Jc0.6.