HIGH Tc SUPERCONDUCTING OXIDE SANDWICH STRUCTURES AND TUNNEL JUNCTIONS
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
Thin superconducting oxide films of the YBaCuO composition ( 1- 2-3 ) have been made which are superconducting to temperatures of about 90oK. These films are difficult to utilize in a layered or sandwich structure due to the roughness of the ceramic film (roughnesses on the order of 0.5 mm can often be seen in nominally 1 micrometer thick films). A second difficulty in making superconductor-insulator-superconductor (SIS) sandwich structures is in making a thin insulator that can survive the 900oC firing required to make good superconductors. A novel solution to these important problems is herein disclosed. A thin insulating film sandwiched between two high Tc superconductors, as described below, can solve this problem. The YBaCuO composition will be used as an example but any ceramic superconducting film can also be used.