IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Thin Films Wednesday Sessions
       Session TF-WeM

Paper TF-WeM2
Molecular Dynamics Simulations of Self-bombardment of Compact Clusters on Pt(111)

Wednesday, October 31, 2001, 8:40 am, Room 123

Session: Fundamentals of Deposition
Presenter: D. Adamovic, Linköping University, Sweden
Authors: D. Adamovic, Linköping University, Sweden
E.P. Münger, Linköping University, Sweden
V. Chirita, Linköping University, Sweden
L. Hultman, Linköping University, Sweden
J.E. Greene, University of Illinois, Urbana
Correspondent: Click to Email
Studies of low-energy bombardment of two-dimensional (2D) close-packed clusters are of great importance and strongly related to thin film growth. We use embedded-atom method molecular dynamics simulations to monitor the kinetics characterizing the self-bombardment of Pt@sub 3@, Pt@sub 7@ and Pt@sub 19@ clusters on Pt(111) at 1000K. Atoms incident perpendicular to the surface with energies between 5 and 50 eV are followed in separate simulations of ~ 20 ps each. Clusters are divided into different sections, outer, rim and core area respectively. Our simulations reveal three major classes of events. They are cluster preservation, i.e. no change in shape or position, cluster reconfiguration, involving edge-diffusion and/or concerted dimer/trimer gliding and cluster disruption (rim atom scattering and/or total disintegration). Two of the most commonly observed events are the formation of three-dimensional (3D) clusters and the hopping and/or push out/exchange mechanism with rim atoms. Other typical processes observed are the permanent or temporary dislodgement of cluster atoms onto the surface as well as the creation of surface vacancies. For Pt@sub 3@ our results suggest that cluster preservation and reconfiguration events primarily occur with incident atom energies below 25 eV, while cluster disintegration prevails at higher energies. Similar effects are observed for larger clusters, however the energy threshold is not as sharply defined.