MICROSTRUCTURAL AND TRANSPORT-PROPERTIES OF LASER-ABLATED LUBA2CU3O7-DELTA THIN-FILMS

High-quality LuBa2Cu3O7-delta (LBCO) thin films have been grown on [10 0] LaAlO3 by pulsed laser deposition. Microstructural studies have ind icated a high degree of c-axis orientation and an in-plane alignment. Transport measurements carried out on 10 mum wide microbridges of LBCO films have shown high critical current densities in the range 2-5 X 1 0(6) A cm-2 at 77 K. Self-field induced flux creep caused by transport currents has also been studied. However, the thickness-dependent effe ctive microwave surface resistance, R(eff), measured using a microstri p resonator technique at the X band has shown a minimum at 3000 angstr om indicating film degradation above 3000 angstrom.