A-AXIS YBA2CU3O7-DELTA AU INTERFACE CONDUCTANCE-VOLTAGE CHARACTERISTICS/

Conductance-voltage characteristics of interfaces between a-axis YBa2C u3O7-delta (YBCO) thin films and gold are presented. When the gold cou nter electrode is deposited in-situ, the junctions have a specific int erface resistivity in the 10(-9) Omega-cm(2) range, about an order of magnitude lower than nominal in-situ, c-axis YBCO/noble-metal junction s. As with nominal c-axis YBCO/noble-metal junctions, there is clear e vidence at T = 4 K for a peak in the conductance at low bias. In addit ion, a dip in the middle of the broad peak structure was resolved. It appears to be a feature unique to the a-axis YBCO/Au interface.