Bi-Pb-Sr-Ca-Cu-O/MgO superconducting thin films

Bi-Pb-Sr-Ca-Cu-O/MgO thin films were prepared by deposition of an aerosol from aqueous nitrate solutions. To prepare the samples, an experimental design was applied to investigate the influence of nine different variables upon the synthesis of superconducting phases. Within this design, the influence of the chemical composition of the nitrate solutions and the precursor thermal treatment upon formation of the superconducting phases were studied. The T-c values of the samples were used as a quantitative parameter to analyze and optimize various parameters studied in the film preparation. The analysis revealed a significant influence of the Bi and/or the Bi/Pb content as well as that of Cu and the thermal treatment parameters. Results from XRD, SEM, EDS and T-c measurements showed a correlation between the film preparation conditions, the film chemical composition and the formation of superconducting phases. (C) 2000 Elsevier Science S.A. All rights reserved.