Energy corrugation in atomic-scale friction on graphite revisited by molecular dynamics simulations

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• 作者：Xiao-Yu Sun ; Yi-Zhou Qi ; Wengen Ouyang ; Xi-Qiao Feng ; Qunyang Li
• 刊名：Acta Mechanica Solida Sinica
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：32
• 期：4
• 页码：604-610
• 全文大小：1,118 KB
• 刊物类别：Engineering
• 刊物主题：Theoretical and Applied Mechanics
  Mechanics, Fluids and Thermodynamics
  Engineering Fluid Dynamics
  Numerical and Computational Methods in Engineering
  Chinese Library of Science
  
• 出版者：The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of
• ISSN：1614-3116
• 卷排序：32

文摘

Although atomic stick–slip friction has been extensively studied since its first demonstration on graphite, the physical understanding of this dissipation-dominated phenomenon is still very limited. In this work, we perform molecular dynamics (MD) simulations to study the frictional behavior of a diamond tip sliding over a graphite surface. In contrast to the common wisdom, our MD results suggest that the energy barrier associated lateral sliding (known as energy corrugation) comes not only from interaction between the tip and the top layer of graphite but also from interactions among the deformed atomic layers of graphite. Due to the competition of these two subentries, friction on graphite can be tuned by controlling the relative adhesion of different interfaces. For relatively low tip-graphite adhesion, friction behaves normally and increases with increasing normal load. However, for relatively high tip-graphite adhesion, friction increases unusually with decreasing normal load leading to an effectively negative coefficient of friction, which is consistent with the recent experimental observations on chemically modified graphite. Our results provide a new insight into the physical origins of energy corrugation in atomic scale friction.KeywordsStick–slip frictionEnergy corrugationMolecular dynamics simulationGraphite