Contrast in nanoscale friction between rotational domains of graphene on Pt(111)
Contrast in nanoscale friction between rotational domains of graphene on Pt(111)
复制标题
DOI：
10.1016/j.carbon.2016.11.016
复制
发表时间：
2017-03-01
期刊：
影响因子：
10.9
通讯作者：
Bennewitz, Roland
中科院分区：
文献类型：
--
作者：
Chan, Nicholas;Balakrishna, S. G.;Bennewitz, Roland
石墨烯的纳米级润滑性能取决于化学功能化、吸附剂和与基体的结合。在超高真空条件下，利用高分辨率摩擦力显微镜研究了Pt（111）表面上石墨烯的旋转取向对摩擦力的依赖性，并通过互补模拟进行了解释。横向力揭示了石墨烯结构周期性的原子尺度粘滑运动。此外，侧向力由云纹图案调制，这取决于各自域的旋转。将实验结果与基于Prandtl-Tomlinson模型的摩擦过程模拟和针尖-样品相互作用的原子模拟进行比较，发现侧向力的调制源于Pt（111）和石墨烯域之间的结构不匹配，这些结构不匹配局部固定在衬底上。具有优先取向的畴，如R1度和R24度，似乎比那些不太常见的取向，如R10域表现出更低的平均摩擦。(C) 2016 Elsevier Ltd.版权所有。
The nanoscale lubrication properties of graphene depend on chemical functionalization, adsorbants, and bonding to the substrate. The dependence of friction on the rotational orientation of graphene on a Pt(111) surface was studied by high-resolution friction force microscopy in ultra-high vacuum and interpreted through complementary simulations. Lateral forces reveal an atomic-scale stick-slip motion with the periodicity of the graphene structure. Additionally, the lateral forces were modulated by a Moire pattern, which depends on the rotation of the respective domain. Comparing the experimental results to simulations of the friction process based on the Prandtl-Tomlinson model and to atomistic simulations of the tip-sample interactions, it was found that the modulation of lateral forces originated from a structural mismatch between Pt(111) and graphene domains that were locally pinned to the substrate. Domains with preferred orientations, such as the R1 degrees and the R24 degrees, appeared to exhibit lower average friction than those with orientations less frequently observed, such as the R10 domain. (C) 2016 Elsevier Ltd. All rights reserved.