title: The surface phase diagram of Li/Cu(001) explored by helium atom scattering.
abstract: We use helium atom scattering to investigate the structures formed by Li adsorption onto Cu(001) in the 0-2 ML regime. Submonolayer growth at 180 K proceeds through a sequence of ordered overlayers, including a c(2 × 2) structure at 0.5 ML and a series of 'ladder' superlattices around 0.6 ML. Beyond 1 ML, incommensurate, three-dimensional Li islands develop. A quantum close-coupled scattering analysis is performed to study the empirical He-surface potential of the structurally heterogeneous ladder structures. Good agreement with the measured distribution of diffracted intensity is obtained by describing the He-ladder interaction potential as the summation of only six one-dimensional Fourier components. The fitted potential indicates a remarkably flat surface that is punctuated by substantial, striped protrusions in the electron density. The result is consistent with the formation of one-dimensional Li wires, indicating an inhomogeneous metallization process.
authors.affiliation: Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK. congcong@slac.stanford.edu
authors.forename: Congcong
authors.initials: C
authors.lastname: Huang
authors.forename: D A
authors.initials: DA
authors.lastname: MacLaren
authors.forename: R T
authors.initials: RT
authors.lastname: Bacon
authors.forename: W
authors.initials: W
authors.lastname: Allison