Formation and atomic structure of ordered Sr-induced nanostrips on Ge(100)

作     者：Boris R. Lukanov Kevin F. Garrity Sohrab Ismail-Beigi Eric I. Altman 

作者机构：Center for Research on Interface Structures and Phenomena (CRISP) Yale University New Haven Connecticut 06520 USA Department of Mechanical Engineering and Materials Science Yale University New Haven Connecticut 06520 USA Department of Applied Physics Yale University New Haven Connecticut 06520 USA Department of Physics and Astronomy Rutgers University Piscataway New Jersey 08854 USA Department of Chemical and Environmental Engineering Yale University New Haven Connecticut 06520 USA 

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：2014年第89卷第15期

页      面：155319-155319页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：National Science Foundation through the Yale Materials Research Science and Engineering Center [DMR-1119826] NSF [CNS 08-21132, TG-MCA08X007] 

主　　题：ATOMIC structure SILICON GERMANIUM ALKALINE earth oxides NANOSTRUCTURES SCANNING tunneling microscopy DENSITY functional theory 

摘      要：The deposition of alkaline earths onto Ge(100) surfaces leads to well-ordered arrays of narrow trenches and elongated plateaus that extend for thousands of angstroms. Using scanning tunneling microscopy (STM) in conjunction with density functional theory (DFT), the atomic scale details of these nanostructures are revealed and the driving force responsible for their formation is evaluated. The STM data reveal a dramatic contrast reversal when the polarity of the imaging bias is switched. An energetically favorable structure for the plateaus was found using DFT that can reproduce all of the observed features. This structure is based upon a double dimer vacancy model in which Sr atoms displace two Ge dimers from the surface. Interestingly, the ordered plateau-trench structure is unique to Ge(100) despite the structural and chemical similarities to the Si(100) surface.