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

The energetics of transition and noble metal (Rh, Pd, Cu) vicinal surfaces, i.e., the surface energy, step energy, kink energy and electronic interactions between steps, is studied at 0 K from electronic structure calculations in the tight binding approximation using an s, p and 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 one 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 paid to the domain of orientations (100)-(111). Semi-empirical potentials are shown to be not realistic enough to give a reliable answer for this problem. The results derived from electronic structure calculations predict a variety of behaviours 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.