Different background conductances in the tunneling characteristics of Bi2Sr2CaCu2O8-based junctions

Gaplike structures superimposed on different background behaviors are observed in the tunneling characteristics of Bi-Sr-Ca-Cu-O-based planar junctions. In the case of constant background, the conductance curves are quantitatively modeled by assuming a modified BCS density of states 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 structures. For extremely anomalous backgrounds, we have analyzed the effect that a zero-bias conductance peak, depending on its voltage amplitude, has on the superconducting structures of both the high-T-c material and the conventional counterelectrode