Laser-ablated epitaxial LaAlO3 buffer layers on biaxially textured Ni substrates for superconducting tapes

Reported here is a new epitaxial buffer layer configuration on biaxially textured Ni substrates for high temperature superconducting films. The hetero-epitaxial LaAlO3/SrTiO3/CeO2/Ni structure was grown using pulsed laser deposition and is the first demonstrated epitaxial deposition of LaA10(3) on a metal substrate. This buffer configuration was designed specifically for, but is not limited to, the Tl-based superconducting materials for which LaA10(3) has been shown to be the optimum substrate to date. The epitaxy and crystal quality of these layers were investigated using X-ray diffraction including 0/20 and pole figure analysis, which showed that the consistency of the SrTiO3 orientation requires further optimization. Atomic force microscopy measurements revealed initial films that, although epitaxial, have a cracked morphology. The formation mechanism of these cracks and their subsequent elimination are discussed. (C) 1998 Published by Elsevier Science B.V. All rights reserved.