Fe self-organization on stepped MgO surfaces

In this work we present a study of Fe self-organization on the surface of stepped MgO as a function of deposition temperature and thickness. The Fe morphology results in being very much influenced by the presence on the MgO terraces of a roughness due to exposure of the sample to the air. Because of the additional sites introduced by the MgO roughness, at room temperature Fe nucleates indistinctly on steps and terraces. Dramatic changes in the Fe nucleation appear on increasing the deposition temperature to 800 K. Here Fe diffuses on the MgO terraces and 40% of the clusters nucleate on step edges. This effect is more evident on decreasing the amount of Fe deposit. (C) 2008 Elsevier Ltd. All rights reserved.