Keywords: molecular dynamics, nanoparticles, melting, inelastic collisions, solid-solid transitions, nanotechnology, simulation, nanoparticle deposition, surface effects, volumetric effects, wetting
Molecular dynamics simulations of nanoparticles
Nanoparticles are becoming increasingly important in many areas of nanotechnology. Here we use classical molecular dynamics simulations to investigate the competition between surface and volumetric effects in metal nanoparticles. In particular, we review work on the melting of isolated nanoparticles, solid-solid transitions in nanoparticles and the deposition of nanoparticles on substrates. In all these examples the delicate balance between surface and volumetric effects can lead to a complex dependence of behaviour on size, from non-monoticity to more exotic phenomena that have no counterpart in bulk materials. In melting, we find that the nature of the wetting of the solid by the melt is important in determining both the melting temperature and the nature of the melting transition. Furthermore, we find that the preference of the melt to wet certain facets can induce solid-solid transitions in partially melted particles. Finally, we observe a re-entrant adhesion transition in nanoparticle deposition as the collision switches from elastic to plastic and the particle begins to spread on the surface. These examples provide an interesting insight into nanoparticle physics.