LASER-ABLATION DEPOSITION OF YBA2CU3O7-X THIN-FILMS USING A MICROWAVEPLASMA DISK REACTOR OXYGEN SOURCE

Thin films of YBa2Cu3O7-x were prepared on polished (100) yttria stabi lized zirconia single crystal substrates by pulsed laser deposition in a low-pressure oxygen background (< 10 mTorr) by using a microwave pl asma disk reactor (MPDR) oxygen source. The MPDR oxygen source provide s high ion densities (> 10(10)/cm3) at low pressures (10(-5)-10(-2) To rr), making it possible to form the superconducting YBCO phase in a lo w background pressure of oxygen. The best film was prepared at 4 mTorr and had a T(C) of 79.5 K as-deposited and the measured J(C) was 2.9 X 10(5) A/cm2 at 77 K. Films prepared under the same conditions using m olecular oxygen were nonsuperconducting as-deposited.