STABLE CONDUCTIVE CONTACTS TO HIGH TC SUPERCONDUCTING OXIDES

PRACTICAL APPLICATIONS OF SUPERCONDUCTORS REQUIRES WIRES SURROUNDED BY NORMAL GOOD CONDUCTING MATERIALS FOR STABILITYIN CASES WHEN TEMPERATURES RISE ABOVE TC. EXISTING FABRICATION PROCEDURES FOR THE NEW SUPERCONDUCTING OXIDES (SUCH AS YBA2CU3O7) REQUIRE SINTERING STEPS AT ELEVATED TEMPERATURES MAKING COPPER-SUPERCONDUCTING COMPOSITE CABLE IMPRACTICLE. THE PROPOSED RESEARCH COULD LEAD TO THE DEVELOPMENT OF MULTILAYER STRUCTURES (METAL-TRANSITION LAYER-SUPERCONDUCTOR) WHICH ARE STABLE DURING SINTERING AT 900 DEGREES C AND MAINTAIN LOW CONTACT RESISTANCE TO THE SUPERCONDUCTOR THROUGH MULTIPLE TEMPERATURE CYCLES ABOVE AND BELOW TC. CONDUCTING COMPOUNDS WHICH ARE STABLE IN OXIDIZING AMBIENTS ARE CANDIDATES FOR THE TRANSITION LAYER. SPECIFIC SUGGESTED CONDUCTING COMPOUNDS WILL BE APPLIED TO APPROPRIATE SUBSTRATES. SUPERCONDUCTING OXIDES WILL BE DEPOSITED ON THESE SAMPLES BY SCREEN PRINTING, THEN SINTEREDAT HIGH TEMPERATURE. SAMPLES WILL BE TESTED FOR ELECTRICAL CONTINUITY BETWEEN LAYERS AT HIGH AND LOW TEMPERATURES. EXPERIMENTAL AND THEORETICAL ANALYSIS OF THE CHEMISTRY AND PHYSICS OF THE INTERFACE WILL BE MADE TO GUIDE PHASE II RESEARCH TO IMPROVE THE TRANSITION LAYER BETWEEN METALS AND THE NEW SUPERCONDUCTOR.