Growth processes of magnetic clusters studied by direct simulation Monte Carlo method

Film formation with deposited magnetic clusters has attracted strong attention as a new manufacturing technique to realize high-density magnetic recording media and to create materials with unique magnetic properties. Such clusters are typically obtained by adiabatic expansion of a metal vapor. It is therefore important to clarify the growth mechanism since this has a profound effect on the cluster magnetic moment. In this article a new simulation method based on a combination of Direct Simulation Monte Carlo (DSMC) and a cluster collision model is introduced to examine the effect of experimental conditions in cluster beam growth. We simulate the behavior of clusters and inert gas atoms in the flight path under different experimental conditions. In particular, we find a bimodal size distribution curve and a decreasing average moment as a function of flight path length.