Relaxation and reconstruction on (111) surfaces of Au, Pt, and Cu

TL;DR

This study uses ab initio calculations to analyze the stability and reconstruction patterns of (111) surfaces of gold, platinum, and copper, revealing intrinsic tensile stress and explaining observed surface structures.

Contribution

It provides a theoretical framework combining DFT and a Frenkel-Kontorova model to predict surface reconstructions of noble metal (111) surfaces.

Findings

Gold and platinum surfaces exhibit intrinsic tensile stress.

Reconstruction patterns differ between Au(111) and Pt(111) due to interaction potential details.

Theoretical predictions align with experimental observations.

Abstract

We have theoretically studied the stability and reconstruction of (111) surfaces of Au, Pt, and Cu. We have calculated the surface energy, surface stress, interatomic force constants, and other relevant quantities by ab initio electronic structure calculations using the density functional theory (DFT), in a slab geometry with periodic boundary conditions. We have estimated the stability towards a quasi-one-dimensional reconstruction by using the calculated quantities as parameters in a one-dimensional Frenkel-Kontorova model. On all surfaces we have found an intrinsic tensile stress. This stress is large enough on Au and Pt surfaces to lead to a reconstruction in which a denser surface layer is formed, in agreement with experiment. The experimentally observed differences between the dense reconstruction pattern on Au(111) and a sparse structure of stripes on Pt(111) are attributed to the details of the interaction potential between the first layer of atoms and the substrate.