DIFFERENT BACKGROUND CONDUCTANCES IN THE TUNNELING CHARACTERISTICS OFBI2SR2CACU2O8-BASED JUNCTIONS

Gaplike structures superimposed on different background behaviors are observed in the tunneling characteristics of Bi-Sr-Ca-Cu-O-based plana r junctions. In the case of constant background, the conductance curve s are quantitatively modeled by assuming a modified BCS density of sta tes for the high-T-c material from which Delta=20+/-2 meV is inferred. In the case of linear backgrounds, we have studied the influence that increasing slopes have on the Bi-Sr-Ca-Cu-O superconducting structure s. For extremely anomalous backgrounds, we have analyzed the effect th at a zero-bias conductance peak, depending on its voltage amplitude, h as on the superconducting structures of both the high-T-c material and the conventional counterelectrode.