Dynamics of ripple formation in sputter erosion: nonlinear phenomena

TL;DR

This paper investigates how nonlinear effects influence ripple formation during sputter erosion, revealing that nonlinearities can destroy or rotate ripples over time, affecting surface morphology and measurable parameters.

Contribution

It demonstrates the significant role of nonlinear terms in surface evolution, showing their impact on ripple destruction and rotation beyond linear theory predictions.

Findings

Nonlinear effects can destroy ripples after a certain time.

Nonlinearities can generate rotated ripple structures.

Surface width and erosion velocity indicate morphological transitions.

Abstract

Many morphological features of sputter eroded surfaces are determined by the balance between ion induced linear instability and surface diffusion. However, the impact of the nonlinear terms on the morphology is less understood. We demonstrate that while at short times ripple formation is described by the linear theory, after a characteristic time the nonlinear terms determine the surface morphology by either destroying the ripples, or generating a new rotated ripple structure. We show that the morphological transitions induced by the nonlinear effects can be detected by monitoring the surface width and the erosion velocity.