The thermal stability of an iron/molybdenum bilayer was determined using Rutherford backscattering spectrometry and X-ray diffraction. Substantial interdiffusion (3%) was observed upon annealing at 973 K for one hour. High temperature annealing of Fe/Mo layers in oxygen ambient is therefore not Suitable for the formation of magnetite layers. (c) 2005 Elsevier B.V. All rights reserved.