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 polyc rystalline Ni-based alloy, by using biaxial yttria-stabilized-zirconia (YSZ) intermediate layers formed by off-normal ion-beam-assisted depo sition. Most explicit in-plane alignment was obtained when the YSZ lay er formed with the beam-incident angle of 55-degrees from substrate no rmal. J(c)-B characteristics and angular dependence of J(c) on the mag netic field were measured. 5.0 x 10(5) and 5.5 x 10(4) A/cm2 were obta ined at 77 K with 0 and 8 T, respectively. The distribution of misorie ntation angles of in-plane a and b axes between YBCO grains was evalua ted by both x-ray pole figure measurement and planar observations of t ransmission electron microscopy. 50% of the grains had the misorientat ion angles restricted within +/- 5-degrees. From the image of dislocat ions, the elastic strains at grain boundaries were estimated to be rel axed with lower misorientation angle. The high-J(c) properties are und erstood to be obtained by the current paths through low-angle grain bo undaries.