Atomic structure of high-index Ge surfaces consisting of periodic nanoscale facets
Atomic structure of high-index Ge surfaces consisting of periodic nanoscale facets
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由周期性纳米级小面组成的高折射率Ge表面的原子结构
DOI：
10.1103/physrevb.56.12308
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发表时间：
1997
影响因子：
3.7
通讯作者：
W. Yang
中科院分区：
文献类型：
--
作者：
Z. Gai;R. Zhao;H. Ji;Xiaowei Li;W. Yang
我们用扫描隧道显微镜(STM)和低能电子衍射仪研究了清洁和良好退火态的Ge(103)表面，其表面呈现出大的(103)阶梯，以及由(105)、{216}和{8116}小面组成的帐篷状突起。在扫描隧道显微镜图像的基础上，提出了$(103)1\ifmmodeTimes\Else\TextTimes\FI，$(216)1\ifmmodeTimes\Else\TextTimes\FI，1和$(105)1\ifmmodeTimes\Else\TextTimes\FI2$表面的原子模型，以供进一步研究。前两个表面只由纳米级的(113)梯级组成，因此属于(113)族，而后者只由纳米级的(001)级梯级组成，因此属于(001)族。$(105)1\ifmmodeTimes\Else\TextTimes\FI2$重建所组成的迷你(001)阶地形成了一个棋盘图案，从而暗示了重建背后的应力松弛驱动力。这些表面结构证明了Herring的刻面定理在原子尺度下是有效的，只要原子尺度的刻面可以通过低能边和/或角连接成一个大的表面。
We have studied the clean and well-annealed Ge(103) surface with scanning tunnel microscopy (STM) and low-energy electron diffraction, whose morphology exhibits large $1\ifmmode\times\else\texttimes\fi{}4$ reconstructed (103) terraces along with tentlike protrusions consisting of (105), {216}, and {8 1 16} facets. On the basis of the STM images, atomistic models have been proposed for the $(103)1\ifmmode\times\else\texttimes\fi{}4,$ the $(216)1\ifmmode\times\else\texttimes\fi{}1,$ and the $(105)1\ifmmode\times\else\texttimes\fi{}2$ surfaces for further investigations. The former two surfaces consist of only nanoscale (113) terraces and hence belong to the (113) family while the latter consists of only nanoscale (001) terraces and thus belongs to the (001) family. The mini (001) terraces that the $(105)1\ifmmode\times\else\texttimes\fi{}2$ reconstruction consists of, form a checkerboard pattern, thus implying a stress-relaxation driving force behind the reconstruction. These surface structures demonstrate that Herring's faceting theorem could be valid down to atomic scales, provided that the atomic-scaled facets could be connected into a large surface by low-energy edges and/or corners.