A Barrier Potential Calculation for Tunneling Electrons at a Metal-Metal Interface

The interface potential for tunneling electrons between two interface metals has been obtained as the sum of a local and a nonlocal contribution, the last one introducing image force effects. Our results show that the image potential is the dominant effect for interface distances between metal surfaces greater than 10 Å. For smaller distances, local effects control the barrier height. We have calculated this barrier height for distances between 5 and 10 Å and found its value ranging between 1.2 and 2.4 eV in good agreement with other independent evidence.