Phenomenology of YBa2Cu3O7-x grain boundary Josephson junctions irradiatedby an electron beam

Electron beam irradiation has been used to induce controllable variations i n the properties of YBa2Cu3O7, biepitaxial grain boundary Josephson junctio ns. Electron irradiation decreased the critical current of the junctions Ic and increased the normal state specific resistivities. The junction parame ters can be adjusted controllably by applying an appropriate dose. The orig inal properties of the junctions could be partly restored by isothermal ann ealing A correlation between the transport properties and the microstructur e was obtained by determining the ratio of a barrier thickness to the diele ctric constant of the junctions with different barriers. The experiment als o demonstrates frequency tunability in a resonant soliton oscillator. Preli minar results of irradiation on (103) YBCO films have been given demonstrat ing differences from data on c-axis films, as partly expected from the anis otropy of these materials.