科研之友
微信
新浪微博
Facebook
分享链接
摘要
The surface diffusion of Co atoms on the Cu clusters with decahedral, cuboctahedral, and icosahedral structures are studied using the nudged elastic band method along with an analysis embedded atom method. The calculated energy barriers show that the exchange is easier than the hopping as the Co atom diffuses from the {111} to {100} facet. The hopping mechanism is favored for the diffusion between the adjacent {111} facets as the Co adatom on the decahedron and icosahedron. On this basis, atom-by-atom growth molecular dynamics simulations are used to study the structure of the Co-Cu cluster. As Co atoms are deposited onto the Cu decahedron or cuboctahedron, we found that Co atoms only occupy {100} facets. So a Co atom belt on the surface of the Cu decahedral cluster is observed. For Co atoms on the Cu icosahedron, an anomalous core-shell structure, where the Co atoms with a larger surface energy lie on the shell and the Cu atoms with smaller surface energy occupy the core, is observed.
