Nucleation and growth kinetics of gold nanoparticles on MgO(100) studied by UHV-AFM

Nucleation kinetics of gold on MgO(1 0 0) has been, for the first time, studied in situ by atomic force microscopy (AFM). The density of clusters first increases and reach a saturation value before to decrease when the coalescence stage is reached. The saturation density of clusters decreases when the substrate temperature increases following an Arrhenius law with an activation energy of 0.12 eV. It is shown that the same behaviour occurs for the, previously studied, nucleation of Ag and Pd on MgO(1 0 0). In each case the activation energy is proportional to the calculated adsorption energy of a single metal atom on the MgO(1 0 0) surface. (C) 2003 Elsevier B.V. All rights reserved.