Propagation of Ripples in Monte Carlo Models of Sputter Induced Surface Morphology

TL;DR

This study uses Monte Carlo simulations to analyze ripple propagation on surfaces caused by ion beam bombardment, highlighting the influence of temperature and material properties on ripple velocity and wavelength.

Contribution

It introduces a Monte Carlo model incorporating two different surface diffusion mechanisms to study ripple propagation, emphasizing temperature effects and material-dependent behaviors.

Findings

Ripple velocity and wavelength depend on sputtering timescale

Ripple velocity shows strong temperature dependence

Ripple velocity vanishes before the ripple pattern

Abstract

Periodic ripples generated from the off-normal incidence ion beam bombardment of solid surfaces have been observed to propagate with a dispersion in the velocity. We investigate this ripple behaviour by means of a Monte Carlo model of the erosion process, in conjuction with one of two different surface diffusion mechanisms, representative of two different classes of materials; one is an Arrhenius-type Monte Carlo method including a term (possibly zero) that accounts for the Schwoebel effect, the other a thermodynamic mechanism without the Schwoebel effect. We find that the behavior of the ripple velocity and wavelength depends on the sputtering timescale, qualitatively consistent with experiments. Futhermore, we observe a strong temperature dependance of the ripple velocity, calling for experiments at different temperatures. Also, we observe that the ripple velocity vanishes ahead of the periodic ripple pattern.