Statistical preparation and characterization of Bi-based 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 synthesis of superconducting phases. Within this design, the influence of chemical composition of the nitrate solutions and the precursor thermal treatment upon formation of superconducting phases were studied. The Tc 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 Bi/Pb content as well as that of Cu and thermal treatment parameters. Results from XRD, SEM, EDS and Tc measurements showed correlation between the film preparation conditions, film chemical composition and the formation of superconducting phases.