Molecular Physics seminar

Friction and Structure of Graphitic Systems

by Merel van Wijk (Radboud University Nijmegen)

Europe/Stockholm
FA31

FA31

Description
Graphite is a prototype material for friction. The strong in-plane bonds and weak interlayer interactions make out-of-plane displacements easy while preserving the in-plane crystalline structure. We will show a few examples of atomistic simulations (a graphene flake on graphite and graphene as a coating for diamond) where these properties affect friction and wear. The combination of graphene with other layered materials, such as h-BN, has also been suggested as a system with very low friction. Due to the different lattice constants, moiré patterns are visible, for which an incommensurate-commensurate transition has been recently observed. Here we examine this possibility using atomistic simulations and show that the nanoscale moiré pattern resembles the potential energy surface at the atomic scale, acting as a magnifying glass.