The surface hydro-oxidation of LaNiO3-delta thin films

The chemical structure and possible hydro-oxidation of LaNiO3-delta films were studied by means of tuneable high-energy X-ray photoelectron spectroscopy using synchrotron radiation. It was shown that the hydroxyl-containing phase, located near the film surface, may be attributed to the lanthanum, and nickel hydroxide species. The thickness of a hydroxide-enriched layer was estimated from the oxide/hydroxide ratio measured at normal and grazing conditions. The hydroxide layer thickness was about 2 nm for step and/or exponential hydroxide spatial distribution. (C) 2008 Elsevier Ltd. All rights reserved.