2003/11/30 by Yoram Burak, Y. Burak, David Andelman +3 · 4 citations
Chemistry · Decision Sciences · Earth and Planetary Sciences · Physics and Astronomy · #Electrostatics and Colloid Interactions #Geophysical and Geoelectrical Methods #Scientific Measurement and Uncertainty Evaluation #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.70.016102
published as Phys. Rev. E 70, 016102 (2004) · 19 pages, 12 figures
arxiv created 2004/01/20 · openalex publication_date 2004/07/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present a model for the ion distribution near a charged surface, based on the response of the ions to the presence of a single test particle. Near an infinite planar surface this model produces the exact density profile in the limits of weak and strong coupling, which correspond to zero and infinite values of the dimensionless coupling parameter. At intermediate values of the coupling parameter our approach leads to approximate density profiles that agree qualitatively with Monte Carlo simulation. For large values of the coupling parameter our model predicts a crossover from exponential to algebraic decay at large distance from the charged plate. Based on the test-charge approach we argue that the exact density profile is described, in this regime, by a modified mean-field equation, which takes into account the interaction of an ion with the ions close to the charged plate.