Influence of the carrier gas on the formation of iron nano-particles from the gas phase:: A molecular dynamics simulation study.

Simulations of the growth of iron clusters have been performed by molecular dynamics simulation with an effective many-body potential suitable for modeling metal-metal interactions. Within this embedded atom method, the energetic contribution of the delocalised electrons are modelled effectively by a function of the local electron density. In the simulations, the heat produced upon particle formation is removed by a carrier gas thermostat. The influence of the amount of carrier gas on the growth process is the main focus of this work. We find an acceleration of the cluster growth with an increasing amount of carrier gas. The formation of the structure of the clusters follows this acceleration as well as the development of the temperature of the iron atoms in the systems. On the other hand, the heating rate of the iron atoms caused by the particle formation increases with an increasing amount of carrier gas. Finally, we have extrapolated the temperature maximum of the iron atoms to a large amount of carrier gas. It was found to be about 1.7 times the temperature of the carrier gas. (c) 2005 Elsevier B.V. All rights reserved.