Coarsening dynamics at unstable crystal surfaces

TL;DR

This paper investigates the coarsening dynamics of crystal surfaces undergoing morphological instabilities due to growth or erosion, analyzing different physical mechanisms and their effects on pattern evolution over time.

Contribution

It provides a comparative analysis of coarsening processes driven by kinetic, energetic, and athermal instabilities on crystal surfaces.

Findings

Different instability types lead to distinct coarsening behaviors.

Pattern sizes can grow indefinitely or be limited by physical factors.

The study highlights key physical ingredients influencing surface morphology evolution.

Abstract

In this paper we focus on crystal surfaces led out of equilibrium by a growth or erosion process. As a consequence of that the surface may undergo morphological instabilities and develop a distinct structure: ondulations, mounds or pyramids, bunches of steps, ripples. The typical size of the emergent pattern may be fixed or it may increase in time through a coarsening process which in turn may last forever or it may be interrupted at some relevant length scale. We study dynamics in three different cases, stressing the main physical ingredients and the main features of coarsening: a kinetic instability, an energetic instability, and an athermal instability.