Superconducting properties of Y-Ba-Cu-O thin films grown in situ by laser ablation

Thin films of YBa2Cu3Oy have been grown in situ on (100) SrTiO3 and (100)MgO, by pulsed excimer laser evaporation from a stoichiometric target. The substrate temperature was adjusted at 750°C by using a CO2 laser as the heating source and the oxygen partial pressure during the deposition was about 0.3 mbar. The samples have been patterned in the shape of lines 0.2 mm long and of widths between 5?m and 20?m. DC transport critical currents have been investigated as a function of temperature and of applied magnetic field up to 6T.