Diffusion of platinum adatoms and dimers on Pt(111) surface by molecular‐dynamics simulation

Abstract

Abstract We present an interatomic potential for Pt within the second‐moment approximation of the tight‐binding theory. The potential was obtained by fitting to the total energy of the metal, computed by first‐principles augmented‐plane‐wave calculations as a function of the volume. This was used, in tandem with molecular‐dynamics simulations, to study the diffusion of Pt adatoms and dimers on Pt(111) surface. The diffusion coefficient of the adatoms and dimers was computed and was found to present Arrhenius behavior. The migration energies and preexponential factors for hopping diffusion mechanism were determined as well and compared with experimental data obtained by scanning tunnelling microscopy and field ion microscopy methods. Both quantities were found to be in good agreement with measurements. Moreover, a concerted adatom exchange diffusion mechanism was investigated at high temperatures, where there is an involvement of more than one surface atom. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010