亚单层铋在Cu(111)上的生长  

Growth of submonolayer bismuth on Cu(111)surface

作　　者：王巨丰 马传许 杜宏健 王兵 WANG Ju-feng;MA Chuan-xu;DU Hong-jian;WANG Bing(Hefei National Laboratory for Physical Sciences at the Microscale,Department of Physics,University of Science and Technology of China,Hefei Anhui 230026,China)

机构地区：[1]中国科学技术大学合肥微尺度物质科学国家研究中心,物理系,安徽合肥230026

出　　处：《电子显微学报》2022年第4期452-458,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.12074359);中国科学院基金资助项目(No.XDB36020200).

摘　　要：半金属铋(Bi)在贵金属表面有多种多样的生长结构,本文利用扫描隧道显微术系统地研究了温度和覆盖度对Bi在Cu(111)表面生长结构的影响。通过对高Bi原子覆盖度(1.5 monolayer,ML)的样品逐步提高退火温度减少其覆盖度,在Bi⁃Cu界面依次获得了非公度的p×√3和公度的[2012]吸附重构与√3×√3R30°表面合金结构。进一步,在低覆盖度(1/3或1/4 ML)时,通过对比室温和200 K低温下Bi在Cu(111)表面的生长模式,分别形成√3×√3R30°表面合金结构与准一维[2012]吸附重构条带,揭示了Bi原子取代Cu原子形成合金的能垒<38.81 meV。此外,对√3×√3R30°表面合金结构的电子态研究观察到了0.25 eV能量位置的Rashba能态峰,并揭示了边界、畴界和点缺陷对Rashba能态空间分布的抑制行为。The atomic structures of submonolayer bismuth(Bi)grown on the Cu(111)substrates have been studied using low⁃temperature scanning tunneling microscopy(STM).The Cu(111)surface with different Bi coverages can be modified by changing the annealing temperature.An ordered p×√3 overlayer,commensurate[2012]overlayer and a √3×√3R30°surface alloy was obtained on Bi⁃Cu interface.The growth behavior at low Bi coverages(1/3 or 1/4 ML)shows that the √3×√3R30°surface alloy phase and the ribbon⁃like[2012]overlayer phase can be obtained when the temperature of the Cu(111)substrate was kept at room temperature and 200 K,respectively.The interaction among Bi atoms on the surface of Cu(111)contributes to the formation of high⁃covered Bi overlayers(>0.5 ML).Surface alloys can be formed on Cu(111)surfaces through the Cu substitution by Bi atom.In addition,the Rashba state at around 0.25 eV in the √3×√3R30°surface alloy was also observed,which can be suppressed by point,line defects and steps.

关 键 词：半金属Bi CU(111) Rashba效应 扫描隧道显微镜 

分 类 号：O484[理学—固体物理] O485[理学—物理] O469