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 YBa (2)Cu(3)O(7)superconducting thin films by pulsed excimer laser ablatio n with a Si heater and composite scanning of laser beam and target. Th e Si heater, composite scanning of laser beam and target, and experime nt results are described. The temperature variation of the Si heater w as < +/-0.5% in a 45 x 40 mm(2) area of 900- 1000 degrees C. Films wer e deposited on LaAIO(3) substrates 35 mm in diameter. The thin films e xhibited a thickness variation of +/-2.5%; the superconducting propert ies were T-c0 = 91 x 0.5 K and J(c) = (3.3+/-0.7) x 10(6) A/cm(2) at 7 7 K and zero magnetic field.