Modelisation of transition and noble metal vicinal surfaces: energetics, vibrations and stability

TL;DR

This paper investigates the energetics, vibrational properties, and stability of transition and noble metal vicinal surfaces using electronic structure calculations and phonon analysis, revealing potential surface faceting behaviors and temperature effects.

Contribution

It introduces a comprehensive study combining electronic structure and phonon calculations to analyze vicinal surface stability and predicts possible faceting phenomena.

Findings

Electronic structure calculations reveal diverse surface behaviors.

Phonon spectra inform on finite-temperature effects.

Predicted surface faceting into different orientations.

Abstract

The energetics of transition and noble metal (Rh, Pd, Cu) vicinal surfaces, i.e., surface energy, step energy, kink energy and electronic interactions between steps, is studied at 0K from electronic structure calculations in the tight-binding approximation using a {\it s, p} and {\it d} valence orbital basis set. Then, the surface phonon spectra of copper are investigated in the harmonic approximation with the help of a semi-empirical inter-atomic potential. This allows to derive the contribution of phonons at finite temperatures to the step free energy and to the interactions between steps. The last part is devoted to the stability of vicinal surfaces relative to faceting with special attention to the domain of orientations (100)-(111). Semi-empirical potentials are shown to be not realistic enough to give a reliable answer to this problem. The results derived from electronic structure calculations predict a variety of behaviors and, in particular, a possible faceting into two other vicinal orientations. Finally, temperature effects are discussed. Comparisons are made with other theoretical works and available experiments.