FABRICATION OF BI-SR-CA-CU-O/BARRIER/BI-SR-CA-CU-O JUNCTION BY TREATMENT WITH CARBONATED WATER

The barrier-layer was successfully fabricated for a preparation of tunneling junction using high T(c) oxide-superconductor such as Bi-Sr-Ca-Cu-O system. Bi2Sr2Ca2Cu3Ox films were used for both superconducting electrodes and the barrier was mainly Bi2SrCaCu2O and the rest that was formed by effects of de-calcium from the first sputtered (2223) film. The reaction of de-calcium occurred immersing it in carbonated water. The change of (2223) phase of BSCCO was confirmed with a comparison of the intensity of X-ray diffraction. The superconductive transition temperature of the junction is different from that of the single film (2223) which had no treatment with carbonated water. Zero-bias-currents through fabricated barrier are observed and the critical currents depend on temperature so far as measured temperature region of 79 K-72 K.