Laser deposition of YBCO monocrystalline thin films on different substrates

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