The reaction between films and substrates was investigated by ICP-AES, SEM and XRD analyses, during the preparation of Ba2YCu3O7-δ(BYCO) superconductor films from the precursor (BaCO3-Y2O3-CuO) films coated on the yttria-stabilized zirconia (YSZ) substrates by the dipping-pyrolysis process. The reaction of the films with the YSZ substrates resulted in the formation of BaZrO3 inside the substrates. Their reactivity increased (1) as the atmosphere was changed as: Ar<O2<air, and (2) as the reaction temperature was raised. With the heat treatment above 900°C in air or O2, the formation of BaZrO3 caused the depletion of Ba in the films, giving rise to the changes in film phases on the substrates as: BYCO→BaY2CuO5+CuO→Y2Cu2O5+CuO. On the other hand, poor reactivity between the films and the substrates was observed during the heat treatment in Ar at 930°C or below. However, films heated at 950°C resulted in BaZrO3 and the mixture of Y2O3 and Cu2O, inside and on the YSZ substrates, respectively.
