LOW RESISTIVITY CONTACTS TO YBACUO SUPERCONDUCTORS USING SILVER-OXIDE POWDER.

LOW RESISTIVITY CONTACTS TO BULK SPECIMENS OF THESE SUPERCONDUCTORS WITH SILVER HAVE BEEN DEVELOPED. IN ORDER TO OBTAIN HOMOGENEOUS MIXTURES THE AUTHORS USED SILVER-OXIDE POWDER. THE CONTACT RESISTIVITY OF 0.19 MICRO-OHM. CM2 WAS OBTAINED BY ANNEALING THE SPECIMEN AT HIGH TEMPERATURE. THE CONTACT WAS MADE TO THE SPECIMEN WHICH WAS THEN EXPOSED TO AIR FOR 110 DAYS: THE CONTACT RESISTIVITY AFTER THIS PERIOD HAD ELAPSED WAS ALMOST THE SAME AS THE CONTACT MADE TO THE FRESH SPECIMEN. IT WAS FOUND THAT ALL THE SILVER-OXIDE IN THE SUPERCONDUCTOR, WAS SEPARATED TO SILVER AND THAT SILVER EXISTED IN ALL VOIDS.