INSULATING BOUNDARY-LAYER AND MAGNETIC SCATTERING IN YBA2CU3O7-DELTA AG INTERFACES OVER A CONTACT RESISTIVITY RANGE OF 10(-8)-10(-3)-OMEGA-CM(2)/

We have measured interface transport in thin-film YBa2Cu3O7-(delta)/Ag interfaces having resistivities ranging from 10(-8) to 10(-3) Ohm cm( 2). Analysis of the interface I-V data indicates that tunneling is the predominant transport mechanism even for the in situ interfaces havin g contact resistivities of 1-7X10(-8) Ohm cm(2). Zero-bias conductance peaks are also observed for the entire range of interface resistivity . The similarity of the zero-bias conductance peaks among these widely varying interfaces suggests that the low-temperature interface transp ort is governed by the same mechanism in each case. These conductance peaks are analyzed in the framework of the Appelbaum-Anderson model fo r tunneling assisted by magnetic scattering from isolated magnetic spi ns in the interface. (C) 1994 American Institute of Physics.