Relative stabilities of adsorbed versus substitutional Al atoms in submonolayer Al/SixGe1−x(111)

作     者：D. V. Gruznev D. A. Olyanich D. N. Chubenko Yu. V. Luniakov I. A. Kuyanov A. V. Zotov A. A. Saranin 

作者机构：Institute of Automation and Control Processes 690041 Vladivostok Russia Faculty of Physics and Engineering Far Eastern State University 690000 Vladivostok Russia Department of Electronics Vladivostok State University of Economics and Service 690600 Vladivostok Russia 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2008年第78卷第16期

页      面：165409-165409页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Russian Foundation for Basic Research [07-02-00650] Russian Federation Ministry of Education and Science [2007-3-1.3-07-01-352] 

摘      要：Using scanning tunneling microscopy, low-energy electron-diffraction observations, and density-functional calculations, the effect of adding Ge to Si(111) substrate on the reconstructions induced by Al adsorption has been studied. It has been found that Ge incorporation alters the relative stability of the reconstructions. In particular, while in the “pure Al/Si(111) system the magic cluster array (α−7×7 phase) is less stable than the 3×3 reconstruction (to which it irreversibly converts upon heating above 600 °C), in the Al/SixGe1−x(111) system magic clusters possess an enhanced thermal stability and persist almost up to the Al desorption temperature of ∼800°. The results of calculations allow us to track the sequential stages of the substitution of Si atoms by Ge in the α−7×7 phase. The general trend found is that adding Ge to Si(111) makes the Al substitutional configuration more preferable than the Al adatom configuration, which is opposite to the relative stabilities of the configurations in the pure Al/Si(111) system.