Molecular dynamics simulations of metal adsorbates on metal surfaces: Rh on Ag(100)

Abstract

The mechanisms of thin-metal film growth on metal surfaces are topics of considerable scientific and technological interest. We have studied the way in which a deposited metal adlayer behaves as a function of metal substrate temperature. Molecular dynamics simulations are used where the interaction energy and the corresponding forces are generated from the recently developed corrected effective medium (CEM) method. In previous work, the CEM method has been shown to predict the geometric and energetic properties of clean and adsorbate-covered surfaces accurately. In this paper, we present results for the Rh on Ag(100) surface system. We show that Rh atoms penetrate the Ag(100) surface by exchanging with Ag atoms in the surface layer structure. Furthermore, this phenomena is found to depend on both the initial coverage of Rh atoms and the Ag substrate temperature. As the substrate temperature increases, the number of Rh atoms exchanging with Ag atoms in the surface increases. Energetic and dynamical aspects of this system are used to understand the reasons why and also the way in which the exchange takes place.