PREPARATION OF LARGE-AREA HIGH-QUALITY YBCO THIN-FILMS BY PULSED-LASER DEPOSITION WITH SI HEATER AND COMPOSITE SCANNING OF LASER AND TARGET

We report on the successful preparation of large-area high-quality YBa2Cu3O7 superconducting thin films by pulsed excimer laser ablation with a Si heater and composite scanning of laser beam and target. The Si heater, composite scanning of laser beam and target, and experiment results are described. The temperature variation of the Si heater was < ±0.5% in a 45×40 mm2 area of 900–1000 °C. Films were deposited on LaAlO3 substrates 35 mm in diameter. The thin films exhibited a thickness variation of ±2.5%; the superconducting properties wereTc0=91×0.5 K andJc= (3.3±0.7)×106 A/cm2 at 77 K and zero magnetic field.