Many-particle diffusion in continuum: Influence of a periodic surface potential

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© 2002 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. http://scitation.aip.org/content/aip/journal/jcp
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Journal Title

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Volume Title

School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2002

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Mcode

Degree programme

Language

en

Pages

7666-7672

Series

The Journal of Chemical Physics, Volume 116, Issue 17

Abstract

We study the diffusion of Brownian particles with a short-range repulsion on a surface with a periodic potential through molecular dynamics simulations and theoretical arguments. We concentrate on the behavior of the tracer and collective diffusion coefficients DT(θ) and DC(θ), respectively, as a function of the surface coverage θ. In the high friction regime we find that both coefficients are well approximated by the Langmuir lattice-gas results for up to θ≈0.7 in the limit of a strongly binding surface potential. In particular, the static compressibility factor within DC(θ) is very accurately given by the Langmuir formula for 0⩽θ⩽1. For higher densities, both DT(θ) and DC(θ)show an intermediate maximum which increases with the strength of the potential amplitude. In the low friction regime we find that long jumps enhance blocking and DT(θ) decreases more rapidly for submonolayer coverages. However, for higher densities DT(θ)/DT(0) is almost independent of friction as long jumps are effectively suppressed by frequent interparticle collisions. We also study the role of memory effects for many-particle diffusion.

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Keywords

diffusion, friction, surface charge, surface dynamics, lattice theory

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Citation

Lahtinen, J. M. & Masin, M. & Laurila, T. & Ala-Nissilä, Tapio & Chvoj, Z. 2002. Many-particle diffusion in continuum: Influence of a periodic surface potential. The Journal of Chemical Physics. Volume 116, Issue 17. P. 7666-7672. ISSN 1089-7690 (electronic). ISSN 0021-9606 (printed). DOI: 10.1063/1.1467908.