Friction force microscopy on well defined surfaces

摘要

Friction force microscopy is implemented in ultrahigh vacuum conditions. Atomic-scale friction is observed on clean surfaces. The onset of atomic-scale stick - slip is observed and discussed in relation to the plucking model. Comparative measurements of AgBr(001) versus NaCl(001) andversus NaCl(001) demonstrate the material-specific contrast of friction. Contrast mechanisms are discussed in relation to these experiments. The role of the chemical nature of the tip is exemplified for the case of Si(111), where wearless sliding is achieved with a PTFE-coated probing tip.