Ein neues Verfahren zur Präparation von Tantal/Silber und Niob/Silber Tunnel- kontakten / A New Method for the Preparation of Tantalum/Silver and Niobium/Silver Tunneling Contacts

Abstract

The preparation starts from material in wire-form. One end of the wire is degassed under ultrahigh-vacuum conditions by a very simple electron-gun and finally melted to form a small smooth sphere. The tunneling barrier is formed by thermal oxidation of the investigated superconductor with oxygen under reduced pressure. The handling of the whole sample (masking and contacting procedures included) is very simple and allows to use this method for systematic tunneling-studies of the transition metal superconductors.