LASER DEPOSITION OF Y-BA-CU-O SINGLE-CRYSTAL THIN-FILMS ON DIFFERENT SUBSTRATES

Superconducting YBa2Cu3O7-x thin films have been grown in situ on (100)-oriented single crystals of LaAlO3, SrTiO3, MgO and Y2O3-stabilized ZrO2 by laser ablation. The epitaxial growth was controlled by the oxygen partial pressure (p(O2)), the substrate temperature T(s) and the laser fluence E during the deposition. Thin films deposited under the optimum conditions (p(O2) = 25 Pa; T(s) = 750-degrees-C; E = 2 J cm-2) show a critical temperature close to 91 K and a transition width less than 1 K regardless of the substrate used. X-ray diffraction analysis shows that the films are highly c axis oriented with a very low mosaic spread. Preliminary measurements performed at 17 K show that the critical current density reaches values over 2 x 10(7) A cm-2 for a sample grown on LaAlO3 under proper deposition conditions.