One-dimensional surface states induced by segregated impurities at transition-metal surfaces

Using ab initio pseudopotential calculations, we have investigated the atomic and electronic structure of a c(3 root 2 x root 2) striped reconstruction, induced by segregated C impurities, at the Fe(001) surface. The segregated C atoms form zigzag chains, which in turn produce one-dimensional Fe surface states near the Fermi energy. We address the influence of the C chains on the local surface atomic geometry, local electrostatic potential, and local density of states, and discuss the formation mechanism of the one-dimensional surface states. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.