Energetics of vicinal surfaces of fcc (111) transition metals

We investigate vicinal surfaces of fee (111) transition metals with close-packed step edges in the tight-binding model. There are two types of such vicinals, A and B, since there exist two types of steps with close-packed edges obtainable on fee (111) surfaces. We calculate energies and energy differences of these vicinal surfaces, their steps, and the interaction between steps for a number of terrace widths. It is seen that steps of type A are preferred for metals with high d band fillings (e.g., Pt) while for lower d band fillings (e.g., Ir), steps of type B are more stable. Finally, the interaction energy between steps is shown to be a (decaying) oscillatory function with both terrace width and band filling. Its magnitude is found to be comparable to the elastic interaction energy between steps at short distances and low temperatures.