Molecular dynamics simulations of nanoscratching were performed. Emphasis was placed upon the relationship between scratching conditions, and defect mechanisms in the substrate. More than 6 million atoms were treated by using the embedded atom method potential. The scratching was simulated by high-speed ploughing, of the (111) surface, by an atomic force microscope tip that was smooth and conical in shape. A repulsive model potential was used to represent the interaction between the atomic force microscope tip and the Al atoms. Dislocations and vacancies were identified as being the 2 major defect types that prevailed during nanoscratching. Their structures and movements were investigated. The glide patterns of Shockley partial dislocation loops depended upon the scratching direction with respect to the slip systems of face-centered cubic single crystals. It was shown that the shape of the atomic force microscope tip directly affected facet formation on the scratched groove. The penetration depth into the substrate during scratching affected surface pile-up, and residual defect generation.

Large-Scale Molecular Dynamics Simulations of Al(111) Nanoscratching. S.Jun, Y.Lee, S.Y.Kim, S.Im: Nanotechnology, 2004, 15[9], 1169-74