In-situ growth of YBa2Cu3O7-x superconducting thin films on (001) MgO by laser ablation method

Abstract A KrF uniform beam excimer laser has been successfully applied to in-situ grow YBa 2 Cu 3 O 7−x superconducting films on (001) MgO substrate. A special designed stainless steel ring placing between substrate and target was used to supply highly uniform flow of N 2 O gas to the laser plume and substrate during deposition. The substrate temperature was kept at 620°c. The thicknesses of the films are 500–2000 A. Typical values of Tc onset, Tc zero and transition width (90%-10%) were measured to be 91, 90, and 1K, respectively. The transport critical current density was measured to be above 3×10 5 A/cm 2 at 77K, without magnetic field. The as-deposited films are smooth, shiny and black with a mirror-like surface morphology. It was found that the surface morphology of thin films prepared by a laser ablation method were highly dependent on the processing parameters.