Fabrication and structural analysis of Al, Ga, and In nanocluster crystals

Artificial nanocluster crystals of In, Ga, and Al were fabricated using a technique in which surface mediated magic clustering is used to achieve identical cluster size while the Si(111)-7x7 surface is used as a template for ordering the clusters. The atomic structures, formation mechanism and stability of the nanoclusters were studied with in situ scanning tunneling microscopy combined with first-principles total energy calculations. Our study shows that delicate control of growth kinetics is extremely important for cluster crystal fabrication, and there is essentially no limitation to this method. The high thermal stability and unique structure make these artificial nanocluster crystals promising for various applications.