Molecular dynamics study of nanoparticle evolution in a background gas under laser ablation conditions

Long-time evolution of nanoparticles produced by short laser interactions is investigated for different materials. To better understand the mechanisms of the nanoparticle formation at a microscopic level, we use molecular dynamics (MD) simulations to analyse the evolution of a cluster in the presence of a background gas with different parameters (density and temperature). In particular, we compare the simulation results obtained for materials with different interaction potentials (Morse, Lennard-Jones, and Embedded Atom Model). Attention is focused on the evaporation and condensation processes of a cluster with different size and initial temperature. As a result of the MD calculations, we determinate the influence of both cluster properties and background gas parameters on the nanoparticle evolution. The role of the interaction potential is discussed based on the results of the simulations. (C) 2008 Elsevier B.V. All rights reserved.