Size-dependent Evolution of Geometric Structures,Energy and Stability of Ni_n(n=3~39) Clusters

The stable geometric structure and energy of Nin(n=3~39) clusters as a function of cluster size are studied by the Monte Carlo simulation. The interaction among atoms is calculated through Lennard-Jones plus Axilrod-Teller potentials. It is found that the clusters grow through adding atoms on one or more surfaces of Ni7 or Ni13 after the cluster size n is larger than 7. It is also found that there exists direct correlation between the stability and geometrical structures of clusters. Relatively, highly symmetry clusters are more stable. In addition, the nickel clusters with fcc-like structure such as Ni33, Ni36 and Ni38 are more stable than their neighboring clusters.