Al-rich Fe0.85Al0.15(1 0 0), (1 1 0) and (1 1 1) surface structures

Abstract Based on previous photoemission findings, the influence of newly observed aluminum surface segregation at the low (1 1 0), (1 0 0) and (1 1 1) index surfaces of the A2 body-centered Fe 0.85 Al 0.15 random alloy is explored. Scanning Tunneling Microscopy, Low-Energy Electron Diffraction and Grazing-Incidence X-ray Diffraction are combined to explore surface structures and topographies. The formation of a surface composition close to the B2 Fe 0.5 Al 0.5 occurs with the appearance of (i) a long-range pseudo-hexagonal incommensurate superstructure with a periodicity of ~ 18  A on the (1 1 0) surface, (ii) a ( 1 × 1 ) termination on the (1 0 0) surface and (iii) a intense vicinal faceting of the (1 1 1) surface in the form of triangular pits.