Superconducting fluctuation effects at a silver-germanium interface

Structures consisting of various layers of Ag and Ge were fabricated in ultrahigh vacuum by quench condensation onto substrates held at liquid-helium temperatures. The electrical conductances of these structures measured ino situ exhibited incomplete superconducting transitions and superconducting fluctuation effects. It is suggested that these may be a consequence of phenomena occurring at a Ag-Ge interface, rather than properties of atomically mixed Ag and Ge.