The growth and superconducting properties of epitaxial Tl2Ba2CaCu2O8 thin films

Epitaxial Tl2Ba2CaCu2O8 thin films have been prepared on (001) LaAlO3 substrates by DC magnetron sputtering and a post-annealing process. X-ray diffraction (XRD) theta -2 theta scans, phi scans and rocking curves proved that the thin films are strongly textured with the c axis parallel to the c axis of the substrate and epitaxially grown on the substrate. A critical current density of 7.6*106 A cm-2 at 77 K has been obtained in zero magnetic field, and the films have strong flux pinning force in high magnetic fields. When magnetic fields were applied perpendicular to the Cu-O plane of the film, the critical current density dropped only by a factor of seven in a 4 T magnetic field and a factor of 15 in a 6.5 T magnetic field.