Ripples and Ripples: from Sandy Deserts to Ion-Sputtered Surfaces

TL;DR

This paper presents a unified theoretical framework for understanding surface morphological evolution during ion sputtering and sandy desert ripple formation, explaining different behaviors in metals and amorphous systems.

Contribution

It introduces a common model for both phenomena, accounting for experimental differences and effects like the Ehrlich-Schwoebel barrier.

Findings

Exponential growth of surface roughness up to a critical point in ion erosion.

Transition from exponential to power-law growth in metals with barrier effects.

Unified description of ripple formation in deserts and ion-sputtered surfaces.

Abstract

We study the morphological evolution of surfaces during ion sputtering and we compare their dynamical roughening with aeolian ripple formation in sandy deserts. We show that the two phenomena can be described within the same theoretical framework. This approach explains the different dynamical behaviors experimentally observed in metals or in semiconductors and amorphous systems. In the case of ion erosion, we find exponential growth at constant wavelength up to a critical roughness $W_c$. Whereas, in metals, by introducing the contribution of the Erlich-Schwoebel barrier, we find a transition from an exponential growth to a power law evolution.