A study was made of the diffusion of Ag-based bimetallic nanoclusters on graphite. Using a molecular dynamics simulation, it was revealed that the Ag clusters exhibited rapid diffusion because of their hexagonal bottom layer. To decrease the rate of diffusion, Pt and Ni were added in order to distort the structure of the alloy cluster. The Pt was expected to provide a stronger force on Ag atoms, while Ni shortened the bond length and thus changed the structure of Ag clusters. This failed to occur because the Pt and Ni atoms formed cores within the Ag clusters. A collision system was designed in which large Ag clusters collided with small Pt or Ni clusters. Upon collision with Pt clusters, the diffusion exhibited little change, because Pt atoms were substituted at the Ag atomic site and formed a perfectly ordered structure. The collision with Ni, however, deformed the bottom layer as well as the overall cluster structure and decreased diffusion.

Molecular Dynamics Simulations of the Diffusion of Bimetallic Nanoclusters Supported on Graphite. Park, J.W., Lee, J.S., Min, C.H., Lee, H.S., Ryu, J.H., Seo, D.H., Lee, H.M.: Journal of Korean Institute of Metals and Materials, 2009, 47[8], 461-5