Thin Solid Films, Vol.516, No.10, 3282-3286, 2008
Structural and electrical characterisation of lanthanum nickelate reactively sputter-deposited thin films
La2NiO4 coatings were co-sputtered on rotating substrates from metallic La and Ni targets in the presence of a reactive argon-oxygen gas mixture. This material is a potential candidate as cathode material for Intermediate Temperature-Solid Oxide Fuel Cells. The structural and chemical features of these films have been determined by X-ray Diffraction and Scanning Electron Microscopy. Their electrical properties have been characterised using the four point probe method and by Complex Impedance Spectroscopy measurements. It is shown that the as-deposited coatings, initially amorphous, crystallise in the LaNiO3 perovskite-type oxide or in the convenient K2NiF4 structure as a function of their composition. The electrical measurements show a clear relation between resistivity and structure of the coatings. Despite electrical resistivity values close to the theoretical ones, the activation energy of a coating presenting the convenient K2NiF4 structure is slightly higher than those given in the literature data. (c) 2007 Elsevier B.V. All rights reserved.
Keywords:magnetron sputtering;La2NiO4;cathode material;intermediate temperature-solid oxide fuel cell;impedance spectroscopy;X-ray diffraction;structural properties;resistivity