SCANNING-TUNNELING-MICROSCOPY .2. CALCULATION OF IMAGES OF ATOMIC AND MOLECULAR ADSORBATES
SCANNING-TUNNELING-MICROSCOPY .2. CALCULATION OF IMAGES OF ATOMIC AND MOLECULAR ADSORBATES
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DOI：
10.1103/physrevb.51.11089
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发表时间：
1995-04-15
影响因子：
3.7
通讯作者：
KENKRE, VM
中科院分区：
文献类型：
--
作者：
BISCARINI, F;BUSTAMANTE, C;KENKRE, VM
上一篇文章 [Phys. 2017] 中提出了一种吸附物扫描隧道显微镜 (STM) 电流理论，重点关注 STM 结中电子运动的相干性影响。 Rev. B 51, 11 074 (1995)]。该理论通过对多个真实 STM 图像的计算进行了说明。尖端、基底和吸附物被视为有限的原子簇。扩展休克尔理论用于计算 STM 电流。使用的基板是Au（111）。为裸露的 Au (111) 表面以及原子和分子吸附物构建了可以直接与实验观察结果进行比较的图像。处理的原子吸附物是Au、Na、H、C和O。处理的分子吸附物是O 2 、CO和苯。与文献中报告的观察结果进行比较，发现与许多特征一致。我们的计算图像表明，在金属 STM 中观察到的巨大波纹可能是由局域表面态之间的非微扰电子传输引起的。讨论了由吸附物引起的非形貌伪影以及图像对尖端-样品分离的依赖性。
A theory of the scanning-tunneling-microscopy (STM) current of adsorbates with focus on effects of coherence in electron motion in the STM junction has been developed in the preceding paper [Phys. Rev. B 51, 11 074 (1995)]. That theory is illustrated through an application to the computation of several realistic STM images. The tip, the substrate, and the adsorbate are treated as finite clusters of atoms. Extended Hückel theory is used to calculate the STM current. The substrate used is Au (111). Images that can be compared directly with experimental observations are constructed for the bare Au (111) surface as well as for atomic and molecular adsorbates. The atomic adsorbates treated are Au, Na, H, C, and O. The molecular adsorbates treated are O 2, CO, and benzene. A comparison is made with observations reported in the literature and agreement with a number of features is found. Our calculated images suggest that observations of giant corrugation in STM of metals might be arising from nonperturbative electron transport between localized surface states. Nontopographical artifacts due to adsorbates and the dependence of the image on the tip-sample separation are discussed.