da Silva A J, Dalpian G M, Janotti A, Fazzio A
Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, SP, Brazil.
Phys Rev Lett. 2001 Jul 16;87(3):036104. doi: 10.1103/PhysRevLett.87.036104. Epub 2001 Jul 2.
We present an ab initio study of the properties of structures composed of two and four Ge atoms adsorbed on the troughs of the Si(100) surface, and we conclude that these structures are all composed of dimers, with a chemical bonding between the adatoms. We compare our calculated local density of states with scanning tunneling microscope (STM) images, and we show that these Ge dimers adsorbed on the troughs between the substrate dimer rows can be identified with the adatom pairs observed experimentally. We also show that the local buckling of the substrate dimers can give rise to similar structures with very different STM images.
我们对吸附在Si(100)表面沟槽上的两个和四个Ge原子组成的结构的性质进行了从头算研究，我们得出结论，这些结构均由二聚体组成，吸附原子之间存在化学键。我们将计算得到的局域态密度与扫描隧道显微镜（STM）图像进行了比较，结果表明，吸附在衬底二聚体行之间沟槽上的这些Ge二聚体可以与实验观察到的吸附原子对相对应。我们还表明，衬底二聚体的局部屈曲可以产生具有非常不同STM图像的类似结构。
