From Zinc Clusters to One-Dimensional Crystals on Quasi-Free Sustained Substrates

By using the Amsterdam density functional (ADF) program based on first-principles, we have in detail investigated the Zn (n) (n = 2-20) clusters, several series of stacked structures, and the growth mechanism of zinc nanorods on silicone oil surfaces, which are isotropic, and can be generally considered as quasi-free sustained substrates. For the Zn (n) (n = 2-20) clusters, some new ground-state structures are found. The additional boundary atoms can enhance the stability of the stacked structures containing unit cells. The structures from the transverse array of the unit cells on (002) crystal plane are more stable than those stacked along the [002] direction as atomic number increases. The transverse arrayed structures can grow along the [002] direction. However, there is an atomic dislocation between the (002) crystal planes. In fact, the dislocation forms its one side surface of (101). By means of a single point SCF calculation in the ADF program, the adsorption energies per atom on the (101) and (002) crystal planes are calculated. According to the Boltzmann distribution probability law, the adsorption probability on the (101) plane is larger than that on the (002) plane, and the ratio between them is about 24-900. This shows that the Zn nanorods grow preferentially along the [110] direction on the (101) planes. These are in good agreement with our experimental findings.