Tunneling in all-high-Tc edge junctions with deposited barriers

All-high-Tc-material edge junctions consisting of laser-ablated Y-Ba-Cu-O electrodes and an in situ rf-sputter-deposited MgO barrier have been fabricated whose I-V characteristics show tunneling-related effects. These include a junction resistance with an exponential dependence on the nominal-barrier thickness, gaplike structure observed in the conductance curves, and Josephson effects. These properties are very sensitive to the choice of materials-processsing method for the junction interfaces. © 1992 The American Physical Society.