Preparation of YBCO and BSCCO Superconducting Thin Films by a New Chemical Precursor Method

摘要

Homogeneous YBa_2Cu_3O_(7_delta) (YBCO) and Bi_2SrCa_2Cu_2O_(8+y) (BSCCO) precursors were prepared by the reaction of triethanolamine with ethyl acetoacetato complexes of Y,Ba,and Cu and those of Bi,Sr,Ca,and Cu,respectively.These precursors showed melt-spinnability and converted to ceramics on heating with the elimination and combustion of organic groups.Superconductive thin films were prepared by depositing a solution on a substrate by spin-coating,followed by calcination.Epitaxial growth of the YBCO phase,with c axis normal to the substrate,was observed.The critical temperature was 88.7 K and the critical current density at 77 K and 0 T was 5 x 10~5 A/cm~2.On the other hand,the epitaxial growth of the c axis aligned BSCCO phase was observed:the critical temperature was 77 K and the critical current density at 5 K was 6 x 10~4 A/cm~2.