Dresden 2003 – wissenschaftliches Programm
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O: Oberflächenphysik
O 21: Adsorption an Oberfl
ächen II
O 21.10: Vortrag
Dienstag, 25. März 2003, 17:15–17:30, HSZ/03
Two-dimensional self-assembly of a hexagonal superlattice of magnetic adatoms — •Fabien Silly1, M. Pivetta1, M. Ternes1, F. Patthey1, J. P. Pelz2, and W.-D. Schneider1 — 1Institut de Physique de la Matière Condensée, Université de Lausanne, CH-1015 Lausanne, Switzerland — 2Department of Physics, The Ohio State University, Columbus, Ohio 43210
Long-range interactions between adatoms on metal surfaces with surface state electrons have been predicted [1] and were observed recently [2-3]. To date however, this mechanism has not been observed to produce a long-range ordered adatom superlattice. Here we present the observation of a hexagonal two-dimensional superlattice of magnetic adatoms on a metal substrate. Ce adatoms, deposited at 4.8 K on a Ag(111) single crystal surface, self-assemble into large ordered hexagonal domains. We show that the periodicity of the superlattice of 32 Å is caused by the interaction of surface state electrons with Ce adatoms and that the long-range stability of the superlattice is due to a subtle balance between the sample temperature, the surface hopping/diffusion barrier, and the concentration-dependent adatom interaction potential.
[1] K. H. Lau and W. Kohn, Surf. Sci. 75, 69 (1978)
[2] J. Repp et al., Phys. Rev. Lett. 85, 2981 (2000)
[3] N. Knorr et al., Phys. Rev. B. 65, 115420 (2002)