DETECTION OF THE PROXIMITY EFFECT IN AU YBCO BILAYERS AT 77 K WITH THE AID OF A LOW-TEMPERATURE SCANNING TUNNELING MICROSCOPE/

The characteristic features of the conductance of a tunneling contact, formed by a microscope tip and an Au/YBCO sandwich, are investigated with the aid of a scanning tunneling microscope. It is shown that ther e exist three types of dependences of the conductance of the structure on the applied voltage, which are distinguished by the position of th e characteristic features on the voltage axis. It is established that this difference is due to the local characteristics of the proximity e ffect in gold films on a high-ir, superconductor surface. It is conclu ded that the transmittance of the YBCO/Au boundary is spatially strong ly nonuniform. (C) 1996 American Institute of Physics.