Hamburg 2001 – wissenschaftliches Programm
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O: Oberflächenphysik
O 17: Adsorption an Oberfl
ächen (II)
O 17.9: Vortrag
Dienstag, 27. März 2001, 13:15–13:30, C
Xe adsorption on metal surfaces - a DFT and kMC study — •Juarez L.F. Da Silva1, B. Lehner2, C. Stampfl1,3, M. Hohage2, P. Zeppenfeld2, and M. Scheffler1 — 1Fritz-Haber-Institut, Berlin, Germany — 2Johannes-Kepler-Universität Linz, Linz, Austria — 3Northwestern University, Evanston, USA
Rare-gas adsorption on surfaces has a long tradition in serving as model system in condensed matter physics due to the presummed simplicity of the rare-gas–substrate interaction. The top site preference for Xe adsorption on metal surfaces has been in debate over the last ten years but was recently confirmed by experiment [1] and theory [2] for Cu(111), Pd(111), and Pt(111), and a simple picture for the low-coordination preference was recently proposed [2]. However, the study of temperature effects from first-principles calculations for Xe on metal surfaces has not been performed to date. Using kinetic Monte Carlo (kMC) simulations [3] and a lattice-gas Hamiltonian approach, the desorption process is investigated, e.g., temperature programmed desorption (TPD). We discuss the nature of the lateral interaction energies (two- and three-body terms) derived from DFT-LDA calculations employing the FP-LAPW method for Xe coverages from θXe = 1/3 to 1/9, as required by the kMC scheme to obtain the TPD spectra [4] for Xe adsorption on Pt(111).
[1] Th. Seyller et al., Chem. Phys. Lett. 291, 567 (1998).
[2] J.L.F. Da Silva, C. Stampfl, and M. Scheffler, in preparation.
[3] B. Lehner, et al., Surf. Sci. 454, 251 (2000).
[4] W. Widdra, et al., Phys. Rev. B 57, 4111 (1997).