Analysis of tip stability in adhesion process in AFM using potential energy surface: Stability versus dissipation

We analyze the stability of the atomic configurations of tips in the adhesion process in noncontact atomic force microscopy (AFM) using a potential energy surface (PES). We calculate the PES for two types of atomic configurations of the tip as typical cases of reconstruction and irreversible change during the adhesion process. The stability of the tips after atomic contact with the surface is explained on the basis of the calculated PESs, which are affected by the strength of the atomic bond between the tip and the surface. It is shown from the computational model for the AFM that an unstable tip leads to a larger energy dissipation compared to that for a stable tip.