Effect of Substrate Shape on Friction Regimes and on Tip Jump Probability in Atomic Scale Friction

Abstract

We investigate the effect of the shape potential on the frictional behavior transitions. The Tomlinson parameter for the deformable substrate potential is calculated theoretically and its influence on friction force is studied. Futhermore, effects of temperature and substrate shape on the tip jump probability are presented. We find two critical times, which characterize the tip dynamics. The first critical time is the time spent by the tip to reach next potential minimum and the second is the time at which the tip exhibits an equiprobability of forward and backward jump. We show that these critical times depend strongly on the substrate shape as well as on the temperature.