Structures of self-assembled n -alkanethiols on gold by reflection high-energy electron diffraction
Structures of self-assembled n -alkanethiols on gold by reflection high-energy electron diffraction
复制标题
通过反射高能电子衍射研究金上自组装正烷硫醇的结构
DOI：
10.1039/d0cp02866e
复制
发表时间：
2020
影响因子：
3.3
通讯作者：
Yang, Ding-Shyue
中科院分区：
文献类型：
--
作者：
Ghosh, Mithun;Yang, Ding-Shyue
使用反射高能电子衍射 (RHEED) 研究了化学吸附在 Au(111) 单晶上的长链烷硫醇 (C18H37SH) 的结构。在沉积薄膜中作为主要物质观察到的一级结构包含硫头基下方的金吸附原子。在烷基链向六个方向倾斜的小有序域之间是方位角无序堆积的区域，类似的平均倾斜为 30.2°。相反，在热诱导相中发现金吸附原子的覆盖率显着降低。该超晶格显示出包含两种硫排列的混合物，两者都表现出较小的 S-S 距离，以及脂肪链的配对。然后给出结构转变的微观图景。这些发现证明了如何使用 RHEED 技术来解析界面处具有多级的纳米厚薄膜的结构。
The structures of long-chain alkanethiols (C18H37SH) chemisorbed on an Au(111) single crystal were investigated using reflection high-energy electron diffraction (RHEED). The primary structure observed as a major species in the as-deposited films contains gold adatoms below the sulfur headgroups. Between the small ordered domains with the alkyl chains tilting toward six directions are azimuthally disorderly packed regions, with a similar average tilt of 30.2°. In contrast, a significant reduction in the coverage of gold adatoms is found in the thermally-induced phase. This superlattice is shown to contain a mixture of two sulfur arrangements, both of which exhibit a small S–S distance, and the pairing of the aliphatic chains. A microscopic picture is then given for the structural transition. These findings demonstrate how the RHEED technique may be used to resolve structures of nanometer-thick thin films with multiple orders at the interfaces.