Growth of biaxially oriented conductive LaNiO3 buffer layers on textured Ni tapes for high-Tc-coated conductors

Electrically conductive LaNiO3 buffer layers have been grown on textured nickel tapes by sputter deposition in a reducing atmosphere. These conductive buffered Ni tapes can be employed as long flexible substrates for biaxially aligned high-temperature superconductors, and can electrically stabilize the superconductor during transient loss of superconductivity. Deposition temperatures of about 400 degrees C result in epitaxial growth of LaNiO3 films, while higher deposition temperatures may cause the formation of La2NiO4 films. X-ray theta-2 theta, theta, and phi scans reveal that the LaNiO3 films have good out-of-plane and in-plane orientations of 5 degrees and 9-10 degrees, respectively. Subsequent oxygen anneals at 750 degrees C and 850 degrees C change neither the biaxial orientations of the film nor cause any cracks or other surface defects. The resistivity of the LaNiO3 films can be further reduced by increasing the annealing temperature and oxygen pressure during post-annealing. Highly textured YBa2Cu3O7 (YBCO) films were grown on the LaNiO3-buffered Ni by pulsed laser deposition (PLD). (C) 1999 Elsevier Science B.V. All rights reserved.