Fabrication and characterization of YBa/sub 2/Cu/sub 3/O/sub 7//Au/YBa/sub 2/Cu/sub 3/O/sub 7/ Josephson junctions

All-high-T/sub c/ Josephson junctions have been fabricated in a planar SNS geometry by bridging narrow gaps ( approximately=0.1-0.2 mu m) in epitaxial YBa/sub 2/Cu/sub 3/O/sub 7/ (YBCO) films with Au. The resulting devices exhibit a variety of nonhysteretic I-V characteristics, with I/sub c/R/sub N/ on the order of 0.1 to 10 mV, and exhibit Shapiro steps under microwave irradiation, and weak periodic modulation of the critical current with applied magnetic field. The transport properties of the junctions appear to be dominated by the Au/YBCO interfaces rather than by the Au itself.