Effects induced by electron beam irradiation on the properties of Y1Ba2Cu3O7-x biepitaxial Josephson junctions

The properties of the Y1Ba2Cu3O7-x biepitaxial Josephson junctions were reproducibly modified by a focused electron beam irradiation of the interface region. The original structures are based on 45 a-axis tilt grain boundaries. The junction parameters can be controllably adjusted by applying an appropriate irradiation dose. Electron irradiation reduced the critical current of the junctions and increased the normal state specific resistivity. The disappearance of the excess current and the shift of the voltage position of the Fiske steps were also observed. Isothermal annealing partly restores the original junction properties. Some aspects of the nature of the grain boundary barriers can be better understood from the study of the properties of irradiated junctions. (orig.)