The surface geometric and electronic structure of the FeAl(110) intermetallic alloy was investigated by scanning tunnelling microscopy and angle-resolved photo-emission spectroscopy. Preferential sputtering results in depletion of Al in the surface region and subsequent annealing promoted surface segregation of Al and gives rise to new reconstructed phases. A bulk terminated surface structure was obtained after annealing the surface to 400C. However, an incommensurate phase develops above 800C with a stoichiometry consistent with an FeAl2 structure in the topmost layer. The angle-resolved photo-emission spectroscopic measurements confirm the Al segregation with increased density of states near the Fermi level. The increased density of states was believed to be due to hybridization between the Fe d and Al sp states. The increased intensity of the Al 2p core level for the incommensurate phase also confirms the higher Al surface concentration for this phase.

Surface Reconstruction of FeAl(110) Studied by Scanning Tunnelling Microscopy and Angle-Resolved Photoemission Spectroscopy. O.Kizilkaya, D.A.Hite, D.M.Zehner, P.T.Sprunger: Journal of Physics - Condensed Matter, 2004, 16[30], 5395-406