Tuning of the periodicity of stable self-organized metallic templates

The atomic and electronic structures of Pb bilayer/Pt(111) are investigated with two theoretical calculations. We find that the stable (2×2)/(3×3) Pb/Pt(111) structure is a promising candidate for being used as a template with self-organized ordered Pb semi-cluster array on the first Pb monolayer. This stable structure can realize the ordered Au single-atom array around the Pb semi-clusters that can cause selective adsorption of noble atoms. The size of Pb magic number semi-cluster plays a more important role in determining the periodicity of the template than the lattice constant misfit between the substrate and the overlayer. This leads to quite a different periodicity between the two stable templates, which are (2×2)/(3×3) Pb/Pt(111) and Pb/Cu(111). Therefore, by considering the size of the stable semi-clusters and carefully selecting different substrate materials, we can tune the density of Pb semi-clusters as the nucleation points and then tune the periodicity of the stable template.