2005/02/14 by Y. L. Wang, Yeliang Wang, Hong‐Jun Gao +5
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Graphene research and applications #Surface and Thin Film Phenomena #cond-mat.mtrl-sci #cond-mat.other #physics.chem-ph #physics.comp-ph
paper · pdf · doi:10.1103/physrevlett.94.106101
published as Phys. Rev. Lett. 94, 106101 (2005). · RevTex4, 4 pages, 4 figures, Fig. 2 of high quality available upon request, to appear in Phys. Rev. Lett
arxiv created 2005/02/14 · openalex publication_date 2005/03/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report scanning tunneling microscopy observations of Ge deposited on the Si(111)-(7 x 7) surface for a sequence of submonolayer coverages. We demonstrate that Ge atoms replace so-called Si adatoms. Initially, the replacements are random, but distinct patterns emerge and evolve with increasing coverage, until small islands begin to form. Corner adatom sites in the faulted half unit cells are preferred. First-principles density functional calculations find that adatom substitution competes energetically with a high-coordination bridge site, but atoms occupying the latter sites are highly mobile. Thus, the observed structures are indeed more thermodynamically stable.