CRITICAL-CURRENT DENSITY IMPROVED BY LASER-IRRADIATION ON GROWING SURFACE IN YBA2CU3OX SUPERCONDUCTING FILMS

Superconducting YBa2Cu3Ox films with c-axis orientation on (100) MgO s ubstrates were prepared by pulsed laser ablation with pulsed laser irr adiation onto the growing film surface. The irradiation gives rise to alpha-axis-oriented crystallites in c-axis-oriented matrix, short c-ax is length and smooth surface morphology without degradation in crystal linity of c-axis-oriented crystal. Critical current density J(c) of th e film is improved by the laser irradiation, resulting in 2.6 X 10(6) A/cm(2) at 77 K and zero field, which is twice that of the non-irradia ted one. In addition, an enhanced pinning effect was also observed at a high field.