Molecular-dynamics simulations of slow copper cluster deposition

In this paper, the dynamic process of ${\mathrm{}\left(\mathrm{Cu}\right)\mathrm{}}_{13}$ cluster deposition on copper substrate is investigated by molecular-dynamics simulations, in which a many-body hybrid potential by combining the Molière potential with the tight-binding potential is used to describe the interactions among copper atoms. The initial energy of the cluster ranges from 2 to 20 eV per atom. By taking "snapshots" and analyzing the energy partition during the deposition process, we find that the cluster atoms could rearrange from the original icosahedral structure to the fcc structure and form epitaxial layers at the end of the simulations. The penetration depths of the cluster atoms increase with the impact energy. The substrate suffers radiation damage when the impact energy of the cluster increases over a value around 20 eV/atom. The energy analyses show that the cluster atoms activate the substrate atoms in the impact region through collective collisions in a very short time (some tenth picoseconds) by providing energies for the migration and reconstruction.