GROWTH AND STRUCTURAL-PROPERTIES OF EPITAXIAL PB(ZRXTI1-X)O-3 FILMS AND PB(ZRXTI1-X)O-3-CUPRATE HETEROSTRUCTURES

We report on the epitaxial growth and structural properties of Pb(ZrxT i1-x)O-3 (PZT) thin films and of epitaxial heterostructures containing metallic DyBa2Cu3O7 (DyBCO) and ferroelectric PZT layers grown using an off-axis rf reactive sputtering technique. On (100) and (110) SrTiO 3 substrates, tetragonal (001) and (011) epitaxial Pb(Zr0.52Ti0.48)O-3 films have been obtained. Extensive characterization on (001) PZT fil ms using x-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), Rutherford backscattering spectroscopy, an d atomic force microscopy reveal a very high degree of structural qual ity, and very smooth surfaces with a root-mean-square roughness of 3 A ngstrom for a 0.5 mu m x 0.5 mu m scan on a 1000 Angstrom thick film. TEM studies on DyBCO-PZT structures reveal sharp and clean interfaces without traces of intermixing. Primary dislocations are observed at th e DyBCO-PZT interface, which do not propagate through the PZT layer. [ 101]-type dislocations are also seen, possibly related to subgrains in the PZT layer, and they show an extended strain field throughout the PZT layer. The possible relation between these structural defects and the nonlinear current-voltage characteristics observed in DyBCO-PZT-Au structures is discussed. (C) 1996 American Institute of Physics.