Fast diffusion of a Lennard-Jones cluster on a crystalline surface

TL;DR

This study uses Molecular Dynamics simulations to investigate how large Lennard-Jones clusters diffuse rapidly on crystalline surfaces, highlighting a vibrational coupling mechanism as a novel explanation for their Brownian motion.

Contribution

It introduces a new mechanism based on vibrational coupling to explain cluster diffusion, expanding understanding of surface diffusion processes.

Findings

Large clusters exhibit rapid diffusion consistent with experiments.

Diffusion is driven by vibrational coupling between the cluster and substrate.

The mismatch in lattice parameters influences the diffusion behavior.

Abstract

We present a Molecular Dynamics study of large Lennard-Jones clusters evolving on a crystalline surface. The static and the dynamic properties of the cluster are described. We find that large clusters can diffuse rapidly, as experimentally observed. The role of the mismatch between the lattice parameters of the cluster and the substrate is emphasized to explain the diffusion of the cluster. This diffusion can be described as a Brownian motion induced by the vibrationnal coupling to the substrate, a mechanism that has not been previously considered for cluster diffusion.