Growth and Characterization of C-Axis Oriented YBa2Cu3O7-x/PrBa2Cu3O7-x Bilayers

Abstract

We report on the preparation and characterization of YBa 2 Cu 3 O 7-x/ PrBa 2 Cu 3 O 7-x bilayers onto (100) SrTiO 3 substrates. The samples have been prepared by sequential dc sputtering processes in high oxygen pressure from stoichiometric targets. The structural characterization of the YBa 2 Cu 3 O 7-x and PrBa 2 Cu 3 O 7-x films and of the bilayers has been performed by means of X-ray diffraction. The Scanning Electron Microscopy analysis has showed that the film surfaces are flat and free of precipitates. A detailed study of the interfaces has been performed by Transmission Electron Microscopy analysis. The electrical resistivity measurements showed for the YBa 2 Cu 3 O 7-x films sharp superconducting transitions at 91.5 K and critical current density of about 106 A/cm 2 at 77 K, while for the PrBa 2 Cu 3 O 7-x films a semiconductor-like behavior has been observed.