Energy-dependent cancellation of diffraction spots due to surface roughening.
Energy-dependent cancellation of diffraction spots due to surface roughening.
复制标题
由于表面粗糙化而导致的衍射斑与能量相关的消除。
作者：
S. Puisto;G. Held;D. King
在200 K时的阶跃扭结Pt{531}表面的低能电子衍射（LEED）图案显示了在异常大的能量范围内（高达100 eV）的衍射斑点的能量依赖性消除。当假设平面几何形状时，这在理论上是不能再现的。一个相对简单的模型粗糙化，然而，涉及0.25 ML的空位和吸附原子导致非常好的协议与实验。在吸附原子或空位覆盖率的很窄范围内强度的抵消是由来自不同高度但相似局部环境的电子的干涉引起的。这是一个罕见的例子，其中集成LEED光斑强度的能量依赖性受到原子长程排列的显著影响。
The low-energy electron diffraction (LEED) pattern of the step-kinked Pt{531} surface at 200 K shows energy-dependent cancellation of diffraction spots over unusually large energy ranges, up to 100 eV. This cannot be reproduced theoretically when a flat surface geometry is assumed. A relatively simple model of roughening, however, involving 0.25 ML of vacancies and adatoms leads to very good agreement with the experiment. The cancellation of intensities within a very narrow range of adatom or vacancy coverages is caused by the interference of electrons emerging from different heights but similar local environments. This is a rare example where the energy dependence of integrated LEED spot intensities is dramatically affected by the long-range arrangement of atoms.