Lee Kee Hag, Suh Youngsun, Lee Changhoon, Hwang Yong Gyoo, Koo H-J, Whangbo M-H
Department of Physical Sciences and Institute of Natural Basic Sciences, Wonkwang University, Iksan 570-749, South Korea.
J Phys Chem B. 2005 Aug 18;109(32):15322-6. doi: 10.1021/jp051248j.
A self-assembled monolayer of 1,10'-phenanthroline (phen) molecules on Au(111) was found to undergo a structural phase transition when the bias voltage is switched in scanning tunneling microscopy (STM) experiments (Phys. Rev. Lett. 1995, 75, 2376; Surf. Sci. 1997, 389, 19). The nature of two bright spots representing each phen molecule in the high-resolution STM images of phen molecules on Au(111) was identified by calculating the partial density plots for a monolayer of phen molecules adsorbed on Au(111) with tight-binding electronic structure calculations. The stacking pattern of chains of phen molecules on Au(111) was explained by studying the intermolecular interactions between phen molecules on the basis of first-principles electronic structure calculations for a phen dimer, (phen)(2). The structural instability of phen molecule arrangement caused by the bias-voltage switch was probed by estimating the adsorbate-surface interaction energy with the point-charge approximation for Au(111).
在扫描隧道显微镜（STM）实验中，当切换偏置电压时，发现1,10'-菲咯啉（phen）分子在Au(111)上的自组装单分子层会发生结构相变（《物理评论快报》，1995年，第75卷，第2376页；《表面科学》，1997年，第389卷，第19页）。通过用紧束缚电子结构计算来计算吸附在Au(111)上的单层phen分子的部分密度图，确定了在Au(111)上phen分子的高分辨率STM图像中代表每个phen分子的两个亮点的性质。通过基于对phen二聚体（phen）₂的第一性原理电子结构计算来研究phen分子之间的分子间相互作用，解释了phen分子在Au(111)上的链堆积模式。通过用Au(111)的点电荷近似来估计吸附质 - 表面相互作用能，探究了由偏置电压切换引起的phen分子排列的结构不稳定性。
