Films with a c-axis orientation were produced by electron beam and thermal evaporation, and were found to be composed of mosaic blocks. The deoxygenated Cu3Ba2YOx films, where x ranged from 6.1 to 6.2, were annealed in an O atmosphere. The change in O concentration of the films during annealing was deduced from the diffraction position of the (00¯1¯1) peak. By using lattice diffusion theory to analyze O diffusion into the films, the activation energies for O diffusion in the tetragonal and orthorhombic phases were obtained and were found to be equal to 1.15 and 1.23eV, respectively. The change in shape of the (00¯1¯1) diffraction peaks indicated that there was a coexisting range of 2 phases near to the transition point. The difference between single crystals and c-axis films was that there were many mosaic boundaries in the c-axis film. Such a boundary acted as a short-circuit for O diffusion and made the diffusion time, during which an equilibrium O concentration was established in the films, much shorter.

Y.X.Chen, J.Zhang, Z.Wu: Superconductor Science and Technology, 1992, 5[8], 463-6