Direct determination by low-energy electron diffraction of the atomic structure of surface layers on a known substrate
Direct determination by low-energy electron diffraction of the atomic structure of surface layers on a known substrate
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通过低能电子衍射直接测定已知基材表面层的原子结构
DOI：
10.1103/physrevb.67.125417
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
D. Saldin
中科院分区：
文献类型：
--
作者：
A. Seubert;K. Heinz;D. Saldin
我们开发了一种直接测定的技术，通过低能电子衍射~LEED！已知衬底上的表面层的原子结构。关键是将多重散射路径分为仅从样品的已知体积散射的路径和包括表面原子散射的路径。在全息类比中，来自前者的贡献之和可以用已知的~来标识！参考波，和那些来自地表的~未知！物波后者可以写成基本物波的线性组合，每一个基本物波都可以看作是一个二维~2D！在覆盖块状晶体的预选3D表面板内的平均原子的超晶格。可以通过最大熵算法确定的该线性展开的系数表示表面板内原子的3D分布。实例给出的应用程序的方法，用于确定结构的吸附在已知的基板从模拟和实验LEED数据。
We develop a technique for the direct determination, by low-energy electron diffraction ~LEED! ,o f the atomic structure of surface layers on a known substrate. The key is the division of multiple-scattering paths into those that scatter solely from the known bulk of the sample and those that include scattering by a surface atom. In a holographic analogy, the sum of the contributions from the former may be identified with a~known! reference wave, and those from the surface with an ~unknown! object wave. The latter may be written as a linear combination of elementary object waves, each of which may be regarded as a renormalized dynamical structure factor of a test two-dimensional ~2D! superlattice of average atoms within a preselected 3D surface slab overlying the bulk crystal. The coefficients of this linear expansion, which may be determined by a maximum entropy algorithm, represent the 3D distribution of atoms within the surface slab. Examples are given of applications of the method for the determination of structures of adsorbates on known substrates from both simulated and experimental LEED data.