ENERGETICS OF VICINAL SURFACES OF FCC(111) TRANSITION-METALS

We investigate vicinal surfaces of fee (111) transition metals with cl ose-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 c lose-packed edges obtainable on fee (111) surfaces. We calculate energ ies and energy differences of these vicinal surfaces, their steps, and the interaction between steps for a number of terrace widths. It is s een that steps of type A are preferred for metals with high d band fil lings (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 wid th and band filling. Its magnitude is found to be comparable to the el astic interaction energy between steps at short distances and low temp eratures.