Biaxial alignment control of YBa2Cu3O7-x films on random Ni-based alloy with textured yttrium stabilized-zirconia films formed by ion-beam-assisted deposition

Biaxially aligned YBa2CU3O7-x (YBCO) films were fabricated on random Ni-based alloy tapes with yttrium stabilized-zirconia (YSZ) buffer layers deposited by ion-beam-assisted deposition (IBAD). Ar+ ion bombardment was found to have two significant effects on the crystalline structure of the YSZ buffer layers: to align a [100] axis with the substrate normal and a [111] axis with the bombarding beam axis, The resulting YSZ films were biaxially aligned on the random polycrystalline tapes, and the azimuthal distribution of the a-and b-axes of YBCO films on the top of the YSZ films was restricted to 10 degrees FWHM. A critical current density (J(c)) of 1.13 x 10(6) A/cm(2) (77 K, 0 T) was obtained, and 1.1 x 10(5) A/cm(2) was maintained at 5 T (77 K, B perpendicular to c). The existence of both intrinsic and extrinsic pinning properties was clearly observed in the angular dependence of J(c) with B perpendicular to I. The longitudinal field effect on J(c) was clearly observed, which indicated straight transport currents, This is evidence for strongly coupled current paths that demonstrate the bulk pinning properties of YBCO.