A single layer of bismuth deposited on the Cu(100) surface forms long range ordered structural phases at various Bi density. A highly ordered c(2 x 2) reconstruction was accomplished at 0.5 ML, further Bi deposition induces a c(9√2 x √2)R45° structure and a subsequent p(10 x 10) phase related to the formation of regular dislocations arrays. The transition from a c(2 x 2) superstructure to the c(9√2 x √2)R45° phase was accompanied by a sudden decrease in the work function. Photoemission measurements reveal that the Bi induced states close to the Fermi level, associated to the c(2 x 2) phase, were strongly quenched when the arrays of dislocations were formed, while at higher binding energies, they undergo an energy shift probably due to a confinement effect. The low-energy single particle excitations and the electron dispersion of the Bi induced states of the c(2 x 2) phase were compared to the electronic states deduced by theoretical band structure obtained by ab initio calculation performed within the embedding method applied to a realistic semi-infinite system.

Bi Ordered Phases on Cu(100) - Periodic Arrays of Dislocations Influence the Electronic Properties. P.Gargiani, M.G.Izzo, F.Bussolotti, M.G.Betti, S.Achilli, M.I.Trioni: Journal of Chemical Physics, 2010, 132[17], 174706