2015/01/16 by Lee, Yi-Hsien, Chatterjee, Kuntal, Fang, Chung-Kai +4
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.1501.03934
With scanning tunneling microscopy, we study the very early stage of Si deposition on a Pb monolayer covered Si(111) surface. We find a special type of Si magic clusters which are highly mobile on the defect-free surface but may be trapped temporarily at certain boundary or defect sites. They may also aggregate and a special aggregate arrangement is found to be stable for one to two days at room temperature. Adding more Si on the cluster aggregate can transform it into a metastable structure. A scenario based on magic clusters and their chemical reactions is proposed to describe the nucleation and growth processes of covalent materials.