In this work we present a study of Fe self-organization on thesurface of stepped MgO as a function of deposition temperatureand thickness. The Fe morphology results in being very muchinfluenced by the presence on the MgO terraces of a roughnessdue to exposure of the sample to the air. Because of the additionalsites introduced by the MgO roughness, at room temperature Fenucleates indistinctly on steps and terraces. Dramatic changes inthe Fe nucleation appear on increasing the deposition temperatureto 800 K. Here Fe diffuses on the MgO terraces and 40% of theclusters nucleate on step edges. This effect is more evident ondecreasing the amount of Fe deposit.' 2008 Elsevier Ltd. All rights reserved.