Rutherford and non-Rutherford elastic scattering analyses have been performed to characterize oxidized iron thin films grown by sputtering. The oxygen depth profiles along the thickness of all the samples have been studied in order to unravel the oxidation process of these samples. The oxygen concentration along the film was related to the sample preparation parameters, resulting in a strong dependence of oxygen depth profile on the substrate temperature during deposition. (c) 2006 Elsevier B.V. All rights reserved.