Abstract
High Tc superconducting YBCO films have been fabricated by in-situ pulsed laser ablation method. The substrates used were SiTiO3 (100) and were heated to 650°C during deposition. X-ray diffraction results indicate that the asdeposited films are highly oriented with c-axis perpendicular to the film surfaces. The critical currents were measured at 77.5 K under different magnetic fields from 0 up to 7 T by using dc four point method. The zero resistance temperature was 89 K and the highest critical current density was 2.5 × 106 A/cm2 at 77.5 K under zero field.