Two-dimensional adatom gas phase on the Si(111)-3×3-Ag surface directly observed by scanning tunneling microscopy

作     者：Norio Sato Tadaaki Nagao Shuji Hasegawa 

作者机构：Core Research for Evolutional Science and Technology The Japan Science and Technology Corporation Kawaguchi Center Building Hon-cho 4-1-8 Kawaguchi Saitama 332-0012 Japan 

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：1999年第60卷第23期

页      面：16083-16083页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

摘      要：Excess Ag adatoms of submonolayer coverages on top of the Si(111)-3×3-Ag surface at room temperature (RT) are known to stay in a two-dimensional adatom-gas (2DAG) phase as a thermodynamical equilibrium state. Reducing the diffusion mobility of the Ag adatoms by cooling the substrate down to 62 K, we could observe migrating adatoms in the 2DAG phase directly by scanning tunneling microscopy (STM). The individual Ag adatoms ceased migration completely at 6 K, showing starlike patterns in STM images. The estimated amount of those Ag adatoms frozen at 6 K was on the order of 0.01 ML, which is in accordance with that at RT obtained previously from electrical conductance measurements.