Abstract
Josephson tunnel junctions have been fabricated using Nb3Sn formed by the reaction at 800°C in a high vacuum between an rf sputtered Nb film and Sn film evaporated over the Nb film. An rf plasma oxidation technique was used for the formation of the tunneling barriers and Pb was deposited for the counter-electrodes. Current-voltage characteristics at 4.2 K show a sharp current rise at a voltage of 4.35 mV. The subgap resistance is more than 7 times the normal resistance. This work shows that high quality Nb3Sn base layers can be formed with a very simple and practical technique suitable for microdevice applications.