PREPARATION AND PROPERTIES OF HIGH-TC SUPERCONDUCTING OXIDE THIN-FILMS

Ba2YCu3O7-δ (BYCO) thin films were epitaxially grown on (110) and (001) SrTiO3 substrates at 600-660°C using the magnetron sputtering method. As-sputtered films were made superconducting by annealing at 800-900°C. The film structures were observed with x-ray diffraction pattern, RHEED and TEM, and thickness dependence of the superconductivity was examined. Furthermore, it was found from that BYCO has large electronic anisotropy, but the scattering process may be due to the same mechanism both in the a-b plane and in the c-axis direction. A new method, a kind of ion-beam-assisted -deposition, was attempted and as-grown films exhibited a superconductivity with a zero resistance temperature above 82 K.