Using a molecular dynamics method and a modified analytic embedded atom potential, the energetic and self-diffusion dynamics of Zr atomic clusters up to eight atoms on the α-Zr(00•1) surface were studied. The simulation temperature ranged from 300 to 1100K and the simulation time varied from 20 to 40ns. It was found that the heptamer and trimer were more stable when compared with other neighboring non-compact clusters. The diffusion coefficients of clusters were derived from the mean square displacement of the cluster mass-center and the present diffusion coefficients for clusters exhibited an Arrhenius behavior. The Arrhenius relationship of the single adatom could be divided into two parts in different temperature ranges because of their differing diffusion mechanisms. The migration energies of clusters increased with increasing the number of atoms in the cluster. The differences in the pre-factors also arose from the diverse diffusion mechanisms. On a 60nm facet, the heptamer could be the nucleus for crystal growth below 370K.

Energetics and Self-Diffusion Behavior of Zr Atomic Clusters on a Zr(0001) Surface. Liu, F., Hu, W., Deng, H., Luo, W., Xiao, S., Yang, J.: Nuclear Instruments and Methods in Physics Research B, 2009, 267[18], 3267-70