Growth of La2NiO4 thin films by chemical vapor deposition

We report on the synthesis of thin films of layered nickelates La2NiO4 by metalorganic chemical vapor deposition (CVD). Films have been prepared in a low pressure CVD reactor on three different substrates: MgO (1 0 0), LaAlO3 (0 1 2) and SrTiO3 (1 0 0). The influence of the substrate on the crystallinity of the films has been studied using X-ray diffraction in the Bragg-Brentano geometry and using a texture diffractometer. Films present an epitaxial growth on the three kinds of substrates with the (1 1 0) plane of the tetragonal cell of La2NiO4 parallel to the surface of the substrates; two other minority orientations with a- and c-axis perpendicular to the surface are also evidenced. Concerning the in-plane orientation of the epitaxial crystallites, films synthesized on LaAlO3 (0 1 2) present a single orientation; in the case of MgO (1 0 0) and SrTiO3 (1 0 0), another in-plane orientation with crystallites tilted from 45 degrees in the plane of the substrate are also present. (C) 2004 Elsevier B.V. All rights reserved.