Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 11: Elektronische Struktur (Experiment und Theorie) I

O 11.7: Vortrag

Montag, 8. März 2004, 17:15–17:30, H44

First Principles Study of Lead Surfaces — •Dengke Yu and Matthias Scheffler — FHI der MPG, Berlin-Dahlem

Motivated by recent experimental work [1] and hitherto conflicting theoretical results of various groups, we studied the surface energies (and other properties) of Pb(111), Pb(100), and Pb(110) surfaces using density-functional theory. All numerical parameters and approximations are carefully checked, as for example the plane-wave cutoff, k-mesh density, slab thickness, and non-linearity of the core-valence exchange-correlation interaction. Using local-density approximation the surface energies (absolute and relative numbers) are found to be in excellent agreement with recent experimental results. However, for the generalized gradient approximation deviations from experimental results are significant. All three surfaces are found to exhibit a pronounced first-layer contraction, followed by a damped oscillatory multilayer relaxation. Our data are consistent with previous low energy electron diffraction analysis. Based on the calculated surface energies we predict a bilayer growth mode for the thin film growth of Pb(100) and Pb(111) on a nonmetallic substrate. For Pb(111) this has been indeed seen in recent experimental studies.[2]

[1] C. Bombis, A. Emundts, M. Nowicki, H. P. Bonzel, Surf.Sci. 511,83 (2002)

[2] M. Hupalo and M. C. Tringides, Phys. Rev. B, 65, 115406 (2002)