Department of Mechanical Engineering, University of California, Merced, CA 95343, USA.
Nanoscale. 2017 Nov 9;9(43):16852-16857. doi: 10.1039/c7nr05326f.
Atomistic simulations were used to study conductance across the interface between a nanoscale gold probe and a graphite surface with a step edge. Conductance on the graphite terrace was observed to increase with load and be approximately proportional to contact area calculated from the positions of atoms in the interface. The relationship between area and conductance was further explored by varying the position of the contact relative to the location of the graphite step edge. These simulations reproduced a previously-reported current dip at step edges measured experimentally and the trend was explained by changes in both contact area and the distribution of distances between atoms in the interface. The novel approach reported here provides a foundation for future studies of the fundamental relationships between conductance, load and surface topography at the atomic scale.
采用原子模拟的方法研究了纳米金探针与具有阶梯边缘的石墨表面之间的界面的电导情况。研究发现，石墨平台上的电导随着负载的增加而增加，并且与界面中原子位置计算出的接触面积近似成正比。通过改变接触位置相对于石墨台阶边缘的位置进一步探索了面积和电导之间的关系。这些模拟再现了实验中测量到的台阶边缘处电流下降的现象，这一趋势可以通过接触面积和界面中原子之间距离分布的变化来解释。本文报道的新方法为未来在原子尺度上研究电导、负载和表面形貌之间的基本关系提供了基础。
