Energy barriers for diffusion on stepped Pt(111) surface

TL;DR

This study uses molecular statics calculations to analyze energy barriers for adatom diffusion near steps on Pt(111), revealing the influence of step microfacets and surface features on diffusion rates.

Contribution

It provides systematic calculations of diffusion barriers near steps with various features on Pt(111) using a semi-empirical potential, offering new insights into surface diffusion mechanisms.

Findings

Lowest barrier for descent occurs at kink or island corners.

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

Barriers vary with surface vicinal to Pt(111).

Abstract

We performed molecular statics calculations of energy barriers for adatom moves in the vicinity of steps on Pt(111) surface. We used the semi-empirical many-body Rosato--Guillope--Legrand potential and we systematically calculated barriers for descent of straight steps, steps with a kink and small islands as well as barriers for diffusion along the step edges. We confirmed that the lowest barrier for descent is for an exchange process near kink's or island's corner on a step with a {111} microfacet. Diffusion along a step with a {111} microfacet is faster than along a step with a {100} microfacet. We also calculated barriers for diffusion on several surfaces vicinal to Pt(111). Our results are compared with previous calculations.