Data di Pubblicazione:
2010
Citazione:
Short-range lateral interactions and depolarization of Na atoms on Cu surfaces / G. Fratesi, A. Pace, G.P. Brivio. - In: JOURNAL OF PHYSICS. CONDENSED MATTER. - ISSN 0953-8984. - 22:30(2010 Jul 13), pp. 304005.1-304005.7. [10.1088/0953-8984/22/30/304005]
Abstract:
The interaction between Na atoms adsorbed on copper surfaces is investigated by means of first-principles simulations based on density-functional theory. In particular, the range of adatom-adatom distances characteristic of coverages of about 0.04-0.08 ML, which have been extensively studied by He3 scattering experiments, is addressed. We found that the dipole-dipole repulsion effectively reproduces the interaction energy for Na-Na distances larger than those within the c(2 × 2) structure. Here, the remaining short-range term is well characterized by an exponential decay and is shown to be independent of the details of the adsorption configuration and of the surface orientation. Depolarization effects of Na adatoms at short and intermediate distances are also discussed, and are shown to play an important role in the dipole-dipole repulsion, though they are not usually accounted for in molecular dynamics simulations of this system.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
CU(001); adatoms; metals; adsorption; molecules; density; sodium
Elenco autori:
G. Fratesi, A. Pace, G.P. Brivio
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