X-RAY-INVESTIGATIONS OF EPITAXIAL BI2SR2CACU2O8-FILMS GROWN ON SRTIO3SUBSTRATES WITH MGO AND CEO2 BUFFER LAYERS FOR THE FABRICATION OF BIEPITAXIAL JOSEPHSON-JUNCTIONS(X THIN)

X-ray diffraction methods have been used for investigation of epitaxia l Bi2Sr2CaCu2O8+x (BSCCO-2212) thin films grown by laser ablation on S rTiO3 substrates buffered with MgO and CeO2. The analysis showed that the films are nearly single crystalline. The deposition of a CeO2 buff er layer improves the microstructure of the BSCCO-2212 film and leads to a light orthorhombic lattice distortion. For the film grown on a Ce O2/MgO (less than or equal to 10 nm) buffer layer system we observed 0 degrees and 45 degrees oriented domains. Using an original method, th e lattice parameters a and b were measured. It was found that the crit ical current j(c) is closely correlated with the structural quality of the films. First experiments were carried out to prepare biepitaxial Josephson junctions based on BSCCO-2212 material.