Relaxation of Surface Profiles by Evaporation Dynamics

TL;DR

This paper investigates the relaxation dynamics of surface profiles, such as steps and sinusoidal grooves, using simulations based on a generalized hypercube stacking model that accounts for temperature-dependent interactions.

Contribution

It introduces a generalized model for surface relaxation that incorporates temperature-dependent next-nearest-neighbor interactions and compares simulation results with continuum theory predictions.

Findings

At T=0, step relaxation follows the t^(1/4) law predicted by continuum theory.

Modified mobility at profile tips yields results consistent with free boundary problem solutions.

Simulations agree reasonably well with theoretical predictions for both steps and sinusoidal grooves.

Abstract

We present simulations of the relaxation towards equilibrium of one dimensional steps and sinusoidal grooves imprinted on a surface below its roughening transition. We use a generalization of the hypercube stacking model of Forrest and Tang, that allows for temperature dependent next-nearest-neighbor interactions. For the step geometry the results at T=0 agree well with the t^(1/4) prediction of continuum theory for the spreading of the step. In the case of periodic profiles we modify the mobility for the tips of the profile and find the approximate solution of the resulting free boundary problem to be in reasonable agreement with the T=0 simulations.