M. Cheon, T. Kim, Y. Park, Dongshin univ., naju, South Korea
High quality Bi
2Sr
2Ca
nCu
n+1O
x superconducting thin films fabricated by using the evaporation method at various substrate temperatures, T
sub, and ozone gas pressures, pO
3. The correlation diagrams of the Bi
2Sr
2Ca
nCu
n+1O
x phases with T
sub and pO
3 are established in the 2212 and 2223 compositional films.
In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on Tsub and pO3. From these results, the thermodynamic evaluation of ΔH and ΔS, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.