Roughening of the Cu(110) Surface

TL;DR

This study investigates the high-temperature roughening transition of the Cu(110) surface using lattice-gas Monte Carlo and molecular dynamics, revealing defect clustering as the atomistic mechanism and estimating relevant time scales.

Contribution

It combines Monte Carlo and molecular dynamics with an anisotropic six-vertex model to analyze surface roughening and defect dynamics at the atomic level.

Findings

Roughening transition occurs around 1000K.

Defect clustering drives the roughening process.

Local roughening time scale is about 100 ps at 1150K.

Abstract

The structure of the Cu(110) surface is studied at high temperatures using a combination of lattice-gas Monte Carlo and molecular dynamics methods with identical many-atom interactions derived from the effective medium theory. The anisotropic six-vertex model is used in the interpretation of the lattice-gas results. We find a clear roughening transition around T_R=1000K and T_R/T_M=0.81. Molecular dynamics reveals the clustering of surface defects as the atomistic mechanism of the transition and allows us to estimate characteristic time scales. For the system of size 50x50, the time scale of the local roughening at 1150 K of an initially smooth surface is of the order of 100 ps.