Structure and formation of the Al(100)-(root 5 x root 5) R27 degrees-Na phase: a LEED, DFT and HRCLS study

Summary, in English

Adsorption of 0.2 ML Na on Al(1 0 0) at room temperature yields a disordered Al(1 0 0)-(1 x 1)-Na phase, which transforms reversibly to a well-ordered Al(1 0 0)-(root5 x root5)R27degrees-Na phase on cooling below 250 K. Based on low energy electron diffraction (LEED) and high resolution core-level spectroscopy (HRCLS) measurements, and on ab initio calculations, it is concluded that the structure of the Al(1 0 0)-(root5 x root5-)R27degrees-Na phase consists of Na atoms occupying substitutional sites. The structural parameters obtained from LEED and density functional theory analyses are in quantitative agreement. Adsorption of 0.2 ML Na at 100 K yields an Al(1 0 0)-c(2 x 2)-Na island structure, which transforms irreversibly into the (root5 x root5)R27degrees-Na structure by annealing above 190 K. The nature of the reversible and irreversible phase transformations to the (root5 x root5)R27degrees structure is investigated by HRCLS and LEED. (C) 2002 Elsevier Science B.V. All rights reserved.

• Author: Mikael Borg; Anders Mikkelsen; Martin Birgersson; M Smedh; Edvin Lundgren; DL Adams; Carl-Olof Almbladh; Jesper N Andersen
• Department/s: Synchrotron Radiation Research; Mathematical Physics
• Publishing year: 2002
• Language: English
• Pages: 267-280
• Publication/Series: Surface Science
• Volume: 515
• Issue: 2-3
• Links: http://dx.doi.org/10.1016/S0039-6028(02)01770-3
• Document type: Journal article
• Publisher: Elsevier
• Topic: Condensed Matter Physics; Atom and Molecular Physics and Optics
• Keywords: low energy electron diffraction (LEED); metals; aluminum; alkali; photoelectron spectroscopy; density functional calculations; photoemission (total yield)
• Status: Published
• ISBN/ISSN/Other: ISSN: 0039-6028