Strain mediated adatom stripe morphologies on Cu<111> simulated

Abstract

Substrate strain mediated adatom configurations on Cu<111> surfaces have been simulated in a coverage range up to nearly 1 monolayer. Interacting adatoms occupy positions on a triangular lattice in two dimensions. The elastic interaction is taken from earlier calculations, short range effects are added for comparison. Dependent on the coverage different morphologies are observed: Superlattices of single adatoms in the 0.04 ML region, ordered adatom clusters in the 0.1 ML region, elongated islands in the 0.3 ML region, and interwoven stripes in the 0.5 ML region. In the region above the sequence is reversed with occupied and empty positions complemented. Stronger short range interactions increase the feature size of the clusters and reduce their lattice order. The influence of the substrate elastic anisotropy turns out to be significant. Results are compared with morphologies observed on Cu<111> surfaces and the applicability of the model is discussed.