Strain mediated adatom stripe morphologies on Cu<111> simulated

TL;DR

This study simulates how substrate strain influences adatom stripe and cluster formations on Cu<111> surfaces across various coverages, revealing different morphologies and the effects of elastic anisotropy and short-range interactions.

Contribution

It introduces a simulation model that captures the coverage-dependent adatom morphologies on Cu<111>, incorporating elastic interactions and substrate anisotropy effects.

Findings

Different adatom morphologies are observed at various coverages.

Stronger short-range interactions lead to larger clusters and less order.

Substrate elastic anisotropy significantly influences morphology formation.

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.