Y-Ba-Cu-O/Au/Nb ramp-type Josephson junctions

Ramp-type junctions connecting the d-wave superconductor YBa2Cu3O7-delta an d the s-wave superconductor niobium are fabricated using a thin gold layer as a chemical barrier. High critical current densities exceeding 5 kA/cm(2) are obtained, The normal state resistivity (R(n)A) values of the junctions are of the order of 0.1 mu Omega cm(2). The magnetic field behavior of the critical current of junctions oriented in the [10l]- and in the [11l]-dire ction of the YBa2Cu3O7-delta is explained in terms of a predominant d(x2-y2 ) Order parameter in the high-T-c superconductor.