Oriented YBa2Cu3O7-δ thick films grown by cryoelectrophoretic deposition

High-Tc thick films of YBa2Cu3O7-δ (YBCO) were grown on Ag substrates by a cryoelectrophoretic technique, i.e. deposited by electrophoresis in a cryogenic environment. The orienting effect is provided by the application of an external magnetic field of small intensity (120 G). After sintering, these films exhibited a superconducting transition at 92 K in the electrical resistivity. Oriented films show significantly enhanced critical current densities. A detailed study of the structural and morphological properties of the film surfaces was undertaken using scanning electron microscopy, x-ray diffraction and scanning force microscopy (SFM). All microscopies revealed different types of film growth induced by the application of an external magnetic field during the cryogenic deposition showing an increasing degree of order with the field intensity (0-120 G). Observations of surface topography as studied by SFM are also discussed. (author)