Surface defects and temperature on atomic friction

TL;DR

This theoretical study investigates how surface defects and temperature influence atomic friction in a minimalistic model, revealing two main mechanisms that alter the mean friction force and slip behavior.

Contribution

It identifies how surface defects modify local potential profiles and slip length distributions, affecting atomic friction in the stick-slip regime.

Findings

Defects change local potential profiles affecting friction.

Defects alter slip length probability distributions.

Temperature, load, and velocity influence defect effects.

Abstract

We present a theoretical study of the effect of surface defects on atomic friction in the stick-slip dynamical regime of a minimalistic model. We focus on how the presence of defects and temperature change the average properties of the system. We have identified two main mechanisms which modify the mean friction force of the system when defects are considered. As expected, defects change locally the potential profile and thus affect the friction force. But the presence of defects also changes the probability distribution function of the tip slip length and thus the mean friction force. We corroborated both effects for different values of temperature, external load, dragging velocity and damping. We show also a comparison of the effects of surface defects and surface disorder on the dynamics of the system.