Pulsed laser deposition of electrochemically active perovskite films

La0.6Ca0.4CoO3 (LCCO) thin films were deposited on MgO(0 0 1) and stainless steel substrates by pulsed reactive crossed-beam laser ablation. High resolution X-ray diffraction (XRD) spectra of the films showed that their quality depends on the oxygen background during cooling. Rutherford backscattering spectrometry measurements reveal that under optimal conditions the films have the same stoichiometry as the original target. X-ray photoelectron spectroscopy (XPS) was applied to characterize the surface of the films, which revealed two oxygen and calcium species: the one at lower binding energy, corresponds to oxygen from the perovskite structure and the one at higher binding energy correspond to Ca-O surface species and adsorbed oxygen. The electrochemical activity of the LCCO films is influenced by the crystallinity of the perovskite electrodes. The structural and electrochemical properties depend on the preparation conditions and substrate. (C) 2002 Elsevier Science B.V. All rights reserved.