In situ preparation of superconducting thick films from rapidly quenched bi-sr-ca-oxide films and surface-oxidized cu plate

Superconducting thick films of Bi₂Sr₂CaCu₂O_y are successfully prepared by in situ reaction between amorphous film of Bi₂SrCaO_x and CuO/Cu substrate. The film of Bi₂SrCaO_x with a 5 µm thickness reacted with the oxidized copper to yield (00l) oriented Bi₂Sr₂CaCu₂O_y films by heating at 820–850°C for 1–60 min in air. These films showed a superconductivity with the maximum T_c(end)=83 K obtained by heating in air at 855°C for 20 min. Similar superconductivity was obtained by heating thick films at 850°C for short periods such as 1 min.