title: LEED I-V and DFT structure determination of the (√3 × √3)R30° Pb-Ag(111) surface alloy.
abstract: The deposition of 1/3 of a monolayer of Pb on Ag(111) leads to the formation of PbAg(2) surface alloy with a long range ordered (√3 × √3)R30° superstructure. A detailed analysis of this structure using low-energy electron diffraction (LEED) I-V measurements together with density functional theory (DFT) calculations is presented. We find strong correlation between experimental and calculated LEED I-V data, with the fit between the two data sets having a Pendry's reliability factor of 0.21. The Pb atom is found to replace one top layer Ag atom in each unit cell, forming a substitutional PbAg(2) surface alloy, as expected, with the Pb atoms residing approximately 0.4 Å above the Ag atoms due to their size difference. DFT calculations are in good agreement with the LEED results.
authors.affiliation: Department of Physics, The University of Liverpool, Liverpool L69 3BX, UK.
authors.forename: I M
authors.initials: IM
authors.lastname: McLeod
authors.forename: V R
authors.initials: VR
authors.lastname: Dhanak
authors.forename: M
authors.initials: M
authors.lastname: Lahti
authors.forename: A
authors.initials: A
authors.lastname: Matilainen
authors.forename: K
authors.initials: K
authors.lastname: Pussi
authors.forename: K H L
authors.initials: KH
authors.lastname: Zhang