Voltage and thermal treatment of tunnel junctions

Abstract

The effect on the zero-bias resistance of Al-Al oxide-Pb tunnel junctions subjected to a fixed voltage (at 77 and 300 K) and to thermal (300 K, open circuit) treatment was investigated. Variations in zero-bias resistance occurred only at 300 K, both with and without applied bias. An attempt was made to separate the voltage from the thermal effect by means of control junctions which, we suppose, show the same relative thermal effect as the biased ones. In thermally treated junctions we found a drastic variation within the first hour. These results are interpreted in terms of ionic mobility.