Stability of superlubric sliding on graphite

TL;DR

This paper investigates the stability of superlubric sliding of graphite flakes, revealing how physical parameters and conditions like size, temperature, and load influence the persistence of low-friction motion.

Contribution

It provides a theoretical analysis of factors affecting superlubric stability, highlighting optimal conditions for maintaining low-friction sliding in graphite.

Findings

Superlubric sliding stability depends on flake size, temperature, and load.

High scanning velocities and specific scan lines can destabilize superlubric motion.

Optimal conditions include large flakes, low temperature, and low load.

Abstract

Recent AFM experiments have shown that the low-friction sliding of incommensurate graphite flakes on graphite can be destroyed by torque-induced rotations. Here we theoretically investigate the stability of superlubric sliding against rotations of the flake. We find that the occurrence of superlubric motion critically depends on the physical parameters and on the experimental conditions: particular scan lines, thermal fluctuations and high loading forces can destroy the stability of superlubric orbits. We find that the optimal conditions to achieve superlubric sliding are given by large flakes, low temperature, and low loads, as well as scanning velocities higher than those used in AFM experiments.