Faceting and stress transfer in the missing-row reconstruction of Ir (110)

TL;DR

This paper uses ab initio calculations to analyze the faceting and stress transfer mechanisms in the missing-row reconstruction of Ir (110) surfaces, revealing the stability of the 3x1 structure and stress redistribution details.

Contribution

It introduces a model based on ab initio results to explain the faceting transition and analyzes stress changes due to reconstruction in Ir (110) surfaces.

Findings

The 3x1 structure is most stable for Ir (110), consistent with experiments.

Reconstruction involves a transition to a (111)-like faceted surface.

Stress increase is due to a shift in tensile and compressive contributions near the surface.

Abstract

We present ab initio total energy and stress calculations for the unreconstructed and (2x1)-missing-row reconstructed Ir (110) and Rh (110) surfaces. We use a model based on ab initio results to show that the (Nx1) reconstruction is a faceting transition to a long-wavelength--corrugated (111)-like surface, and find the 3x1 structure to be the most stable for Ir in accordance with experiment. We then use the stress density to analyze the stress increase upon reconstruction, and find it to be due to a changed balance of tensile and compressive contributions in the near-surface region.