Nobuhiro Ota

YBa2Cu3O7-x Thin Film Prepared by Laser Ablation

High critical current density YBa2Cu3O7-x thin films on (100)SrTiO3 were successfully prepared by laser ablation. The zero resistance transition temperature (Tc(R=0)) was 90.5 K and the critical current density (Jc) at 77.3 K was 8.0×106 A/cm2 under a zero magnetic field. Jc degraded to 1.7×104 A/cm2 in a magnetic field of 8 T parallel to the c-axis of the film, and to 4.0×105 A/cm2 in a magnetic field of 8 T perpendicular to the c-axis of the film. The characteristics of the film, mis-oriented crystallites and stacking faults, were revealed by transmission electron microscopy (TEM).

Structure of High-Tc Superconducting Thin Film by Laser Ablation

High quality YBa2Cu3O7−x thin films were prepared on (100)SrTiO3 substrate by laser ablation. One of the best samples showed the critical current density (Jc) of 8.0x106A/cm2 at 77.3K under a zero magnetic field. The characteristics of this sample were investigated in comparison with the sample which has Jc of 2.0x106A/cm2. The characteristics of the film, mis-oriented crystallites and stacking faults, were revealed by transmission electron microscopy (TEM). Furthermore, the preferential orientations of the film with various preparation conditions by laser ablation were also studied.