Structure and electronic states of vicinal Ag(111) surfaces with densely kinked steps
Structure and electronic states of vicinal Ag(111) surfaces with densely kinked steps
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DOI：
10.1088/1367-2630/aacbb7
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发表时间：
2018-07-04
影响因子：
3.3
通讯作者：
Lobo-Checa, Jorge
中科院分区：
文献类型：
--
作者：
Enrique Ortega, J.;Vasseur, Guillaume;Lobo-Checa, Jorge
由于其不同的物理化学性质和它们作为生长模板的用途，经常研究表现出原子台阶阵列的邻位表面。然而，具有大量低配位扭结原子的台阶表面被广泛忽视，尽管它们具有更高的化学和催化潜力。本文利用弯曲晶体系统地研究了Ag（111）邻位密集扭结台阶表面的平衡结构和电子态。与扫描隧道显微镜，我们观察到一个特殊的结构均匀性，这一类的邻位，反映在平台的大小在所有邻位角的平滑概率分布。这使我们能够观察到，第一，一个微妙的演变的梯田大小分布的梯田宽度的函数，挑战统计模型的步骤晶格，第二，晶格周围的表面状态的共振模式的波动。如角分辨光电子能谱实验所示，表面态受到完全扭结的台阶边缘的更强散射，这在具有相对小的邻角的表面处触发二维带的完全耗尽。
Vicinal surfaces exhibiting arrays of atomic steps are frequently investigated due to their diverse physical-chemical properties and their use as growth templates. However, surfaces featuring steps with a large number of low-coordinated kink-atoms have been widely ignored, despite their higher potential for chemistry and catalysis. Here, the equilibrium structure and the electronic states of vicinal Ag(111) surfaces with densely kinked steps are investigated in a systematic way using a curved crystal. With scanning tunneling microscopy we observe an exceptional structural homogeneity of this class of vicinals, reflected in the smooth probability distribution of terrace sizes at all vicinal angles. This allows us to observe, first, a subtle evolution of the terrace-size distribution as a function of the terrace-width that challenges statistical models of step lattices, and second, lattice fluctuations around resonant modes of surface states. As shown in angle resolved photoemission experiments, surface states undergo stronger scattering by fully-kinked step-edges, which triggers the full depletion of the two-dimensional band at surfaces with relatively small vicinal angles.