Influence of step-edge barriers on the morphological relaxation of nanoscale ripples on crystal surfaces

TL;DR

This paper investigates how step-edge barriers influence the decay of nanoscale ripples on crystal surfaces, revealing that decay rates increase as amplitude decreases, which differs from previous models.

Contribution

It demonstrates that step-edge barriers cause an unconventional decay behavior of surface ripples, with decay rates inversely related to wavelength and amplitude, supported by numerical simulations.

Findings

Decay rate increases with decreasing amplitude.

Decay rate is inversely proportional to the square of the wavelength.

Numerical simulations confirm the theoretical predictions.

Abstract

We show that the decay of sinusoidal ripples on crystal surfaces, where mass transport is limited by the attachment and detachment of atoms at the step-edges, is remarkably different from the decay behavior that has been reported until now. Unlike the decreasing or at most constant rate of amplitude decay of sinusoidal profiles observed in earlier work, we find that the decay rate increases with decreasing amplitude in this kinetic regime. The rate of shape invariant amplitude relaxation is shown to be inversely proportional to both the square of the wavelength and the current amplitude. We have also carried out numerical simulations of the relaxation of realistic sputter ripples.