Molecular dynamics simulation on the deposition behavior of nanometer-sized Au clusters on a Au (0 0 1) surface

The deposition behavior of 300-1500 atom Au clusters was studied with molecular dynamics (MD) using a potential of the embedded atom method (EAM). This study was aimed at examining the possibility of thin-film growth by a cluster as a building unit, which had been suggested in the charged cluster model (CCM). According to the CCM, most of the commercially available thin films were actually cluster-assembled ones although they have been believed to grow by the atomic unit. Small (300 and 500 atoms) and large (1000 and 1500) clusters equilibrated at 1000 K were used as the starting points for the simulation. Small clusters melted during equilibration at 1000 K, while large clusters did not. Clusters of various sizes were deposited on a Au(1 0 0) surface thermostated at 800 K. Within 50 ps, the 300-atom cluster underwent full epitaxial recrystallization with the substrate surface. In contrast, a much longer time was required for the 1000- and 1500-atom clusters to achieve full epitaxial recrystallization. The epitaxial recrystallization behavior of small and large clusters used in this simulation suggests the possibility of thin-film growth by a cluster unit as suggested in the CCM.