Fabrication and Josephson behavior of high-T c superconductor-normal-superconductor microbridges

Abstract

We describe a simple new technique for fabricating superconductor‐normal metal‐superconductor (SNS) microbridges that allows the use of high‐T_c materials. We have used this technique to make the first high‐T_c SNS microbridges, incorporating Nb₃Ge, Nb₃Sn, and Nb as the superconductor, and Cu and Au as the normal metal. These devices have a T_c up to 19 K and exhibit very good electrical characteristics over a wide range of temperatures. Both the dc and the ac Josephson effects are clearly displayed by these junctions.