Energy barriers for diffusion on stepped Rh(111) surfaces

TL;DR

This study systematically calculates energy barriers for adatom diffusion near steps on Rh(111) surfaces, revealing how surface microstructure influences diffusion pathways and probabilities using molecular statics with a semi-empirical potential.

Contribution

It provides detailed barrier data for various step geometries and diffusion directions on Rh(111), enhancing understanding of surface diffusion mechanisms.

Findings

Descent is more probable on steps with {111} microfacet and near kinks.

Diffusion along {100} microfacet steps is faster than along {111}.

Barriers vary across different vicinal surfaces.

Abstract

Energy barriers for different moves of a single Rh adatom in the vicinity of steps on Rh(111) surface are studied with molecular statics. Interatomic interactions are modeled by the semi-empirical many-body Rosato-Guillope-Legrand potential. We calculate systematically barriers for the descent at straight steps, steps with the kink and small islands as well as barriers for diffusion along the step edges. The descent is more probable on steps with a {111} microfacet and near kinks. Diffusion along a step with a {100} microfacet is faster than along a step with a {111} microfacet. We also calculate barriers for diffusion on several surfaces vicinal to Rh(111).