Dynamic friction unraveled using an atomically defined model system

TL;DR

This study combines experimental and theoretical methods to elucidate the atomistic mechanisms of dynamic friction during molecule manipulation on surfaces, revealing how energy dissipation and hysteresis influence friction forces at the nanoscale.

Contribution

It provides a detailed atomistic understanding of dynamic friction during molecule manipulation, integrating AFM, vibrational spectroscopy, and DFT to reveal energy dissipation mechanisms.

Findings

Energy dissipation linked to hysteresis involving an intermediate state

Friction forces can be controlled and optimized at the atomic level

Complete manipulation process of CO on Cu surface characterized

Abstract

The pervasive phenomenon of friction has been studied at the nanoscale by controlled manipulation of single atoms and molecules, which permitted a precise determination of the static friction force necessary to initiate motion. However, much less is known about the atomistic dynamics during manipulation. Here we reveal the complete manipulation process of a carbon monoxide molecule on a copper surface at low temperatures using a combination of atomic force microscopy, vibrational spectroscopy for different isotope molecules and density functional theory. We measured the energy dissipation associated with manipulation and relate its origin to hysteresis involving an intermediate state, which enables an atomistic interpretation of dynamic friction. Our results show how friction forces can be controlled and optimized, facilitating new fundamental insights for tribology.