Fabrication of electrical contacts to YBa/sub 2/Cu/sub 3/O/sub 7-x/ superconductor by molten silver processing

Electrical contacts between silver and YBa/sub 2/Cu/sub 3/O/sub 7-x/ superconductor are fabricated by the molten silver processing. The contact resistance follows a nonlinear relationship with the current density. The DC specific contact resistances corresponding to 30A/cm/sup 2/ and 160A/cm/sup 2/ current density are 1 x 10/sup -8/ ohm-cm/sup 2/ and 2 x 10/sup -7/ ohm-cm/sup 2/ respectively. The recent discovery of superconductivity above 90K in the Y-Ba-Cu-O system has created a great deal of interest in the development of an even better compound and the practical applications of the already confirmed relatively stable YBa/sub 2/Cu/sub 3/O/sub 7-x/ high temperature superconductor (HTSC). Applications for the HTSC compounds and related materials as electronic interconnects, power transmission lines, Josephson junctions and other devices, in addition to fundamental physics and chemistry studies, require (a) fabricating the compounds in forms and patterns that are suitable for each individual application, (b) improving the superconductivity critical current density, and (c) understanding and engineering the interface between HTSC and other materials. In this work, the authors study the silver contacts to YBa/sub 2/Cu/sub 3/O/sub 7-x/ superconductor by a molten silver process in O/sub 2/ at one atmosphere pressure