Growth of superconducting thin films of bismuth-strontium-calcium-copper oxide by organometallic chemical vapor deposition

The first growth of superconducting Bi-Sr-Ca-Cu-O films by organometallic chemical vapor deposition is described. Triphenyl bismuth and beta-diketonates of strontium, calcium, and copper were decomposed thermally at 500°C on MgO substrates in an oxygen-rich atmosphere to produce fine grained or amorphous, dark brown to black films. Subsequent annealing in oxygen yielded gray-black films with thicknesses of 0.95 to 1.25 μm. X-ray analysis indicated the presence of a tetragonal superconducting phase along with other metal oxides. The sheet resistance versus temperature for the sample with the highest T c had a resistive transition with a midpoint at 78.8 K, a width of 7.7 K, and R = 0 at 73.2 K.