Surface vibrational thermodynamics from ab initio calculations for fcc(100)

    Authors

    H. Yildirim; A. Kara; T. S. Rahman; R. Heid;K. P. Bohnen

    Comments

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    Abbreviated Journal Title

    Surf. Sci.

    Keywords

    Density functional theory; Vibrational dynamics; Thermodynamics; Metal; surfaces; RECONSTRUCTED AU(511) SURFACE; MULTILAYER RELAXATION; ELECTRONIC-STRUCTURE; LATTICE-RELAXATION; TRANSITION-METALS; 1ST; PRINCIPLES; GREEN-FUNCTION; FREE-ENERGIES; DYNAMICS; DIFFUSION; Chemistry, Physical; Physics, Condensed Matter

    Abstract

    We present vibrational dynamics and thermodynamics for the (1 0 0) surfaces of Cu, Ag, Pd, Pt and Au using a real space approach. The force field for these systems is described by density functional theory. The changes in the vibrational dynamics and thermodynamics from those in bulk are confined mostly to the first-layer. A substantial enhancement of the low-frequency end of the acoustic branch was found and is related to a loosening of the bond at the surface. The thermodynamics of the first-layer also show significant differences (higher heat capacity, lower free energy and higher mean vibrational square amplitudes) from what obtains in bulk. Comparing these results with those calculated using embedded-atom method potentials, we discovered that for Ag(1 0 0) and Cu(1 0 0), the two methods yield very similar results while for Pd(1 0 0), Pt(1 0 0) and Au(1 0 0) there are substantial differences. (C) 2009 Elsevier B.V. All rights reserved.

    Journal Title

    Surface Science

    Volume

    604

    Issue/Number

    3-4

    Publication Date

    1-1-2010

    Document Type

    Article

    Language

    English

    First Page

    308

    Last Page

    317

    WOS Identifier

    WOS:000274979000011

    ISSN

    0039-6028

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