Superstructures of oxygen and sulphur on a Fe(110) surface via fast atom diffraction
Superstructures of oxygen and sulphur on a Fe(110) surface via fast atom diffraction
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通过快速原子衍射研究 Fe(110) 表面上氧和硫的超结构
DOI：
10.1103/physrevb.79.235425
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发表时间：
2009
影响因子：
3.7
通讯作者：
K. Gärtner
中科院分区：
文献类型：
--
作者：
A. Schüller;M. Busch;J. Seifert;S. Wethekam;H. Winter;K. Gärtner
能量从400 eV到几keV的快氦原子和氢分子从被氧和硫原子覆盖的Fe（110）表面掠射散射，分别形成$c（2\ifmmode\times\else\texttimes\fi{}2）$和$c（1\ifmmode\times\else\texttimes\fi{}3）$超结构。对于沿沿着低折射率方位角方向的散射，我们观察到散射射弹的角分布中的定义的衍射图案。通过对这些衍射图案的评估，我们推导出低折射率轴向通道的宽度、穿过这些通道的相互作用势的波纹以及Fe晶格上方吸附原子的正常位置。我们的分析是基于半经典模型，使用硬壁近似，以及个人的潜力与表面的相互作用的弹丸。通过比较不同模型的结果，我们讨论了表面的几何结构的信息的鲁棒性。
Fast helium atoms and hydrogen molecules with energies from 400 eV up to several keV are grazingly scattered from a Fe(110) surface covered by oxygen and sulphur atoms forming $c(2\ifmmode\times\else\texttimes\fi{}2)$ and $c(1\ifmmode\times\else\texttimes\fi{}3)$ superstructures, respectively. For scattering along low-index azimuthal directions we observe defined diffraction patterns in the angular distributions for scattered projectiles. From the evaluation of those diffraction patterns we derive the widths of low-indexed axial channels, the corrugation of the interaction potential across these channels, and the normal positions of adsorbed atoms above the Fe lattice. Our analysis is based on semiclassical models using hard-wall approximation as well as individual potentials for the interaction of projectiles with the surface. By comparing the results of different models, we discuss the robustness of the information on the geometrical structure of the surfaces.