Thermodynamic conditions for formation of single phase in Bi-superconductor thin films

High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, Tsub, and ozone gas pressures, pO3. The correlation diagrams of the BSCCO phases appearing against Tsub and pO3 have been established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 phases as well as Bi2212 have emerged as stable phases depending on Tsub and pO3. From these results, the thermodynamic evaluations of ΔH and ΔS, which are related with Gibbs’ free energy change for single Bi2212 or Bi2223 phase have been performed.