STRUCTURAL AND TRANSPORT-PROPERTIES OF BIAXIALLY ALIGNED YBA2CU3O7-X FILMS ON POLYCRYSTALLINE NI-BASED ALLOY WITH ION-BEAM-MODIFIED BUFFER LAYERS

Biaxially aligned YBa2Cu3O7-x (YBCO) thin films were produced on polycrystalline Ni-based alloy, by using biaxial yttria-stabilized-zirconia (YSZ) intermediate layers formed by off-normal ion-beam-assisted deposition. Most explicit in-plane alignment was obtained when the YSZ layer formed with the beam-incident angle of 55-degrees from substrate normal. J(c)-B characteristics and angular dependence of J(c) on the magnetic field were measured. 5.0 x 10(5) and 5.5 x 10(4) A/cm2 were obtained at 77 K with 0 and 8 T, respectively. The distribution of misorientation angles of in-plane a and b axes between YBCO grains was evaluated by both x-ray pole figure measurement and planar observations of transmission electron microscopy. 50% of the grains had the misorientation angles restricted within +/- 5-degrees. From the image of dislocations, the elastic strains at grain boundaries were estimated to be relaxed with lower misorientation angle. The high-J(c) properties are understood to be obtained by the current paths through low-angle grain boundaries.