Influence of the finite size on the surface properties of the classical one-component plasma: variational calculations

Publisher Website
Google Scholar
Abstract
The density-gradient expansion, one of the approximation schemes of the density functional theory, is used to investigate the influence of finite size on the surface properties of the classical one-component plasma. Variational calculations are performed within the square gradient approximation for the surface properties of a spherical system. It is found that the calculated ion density profile and surface energy for a small sphere are quite different from those for the planar surface in the weak-coupling regime and in good agreement with the recent Monte Carlo simulations. These results provide further support for the previous argument that the Monte Carlo results for a spherical system could be explained, at least in the weak-coupling regime, by taking into account the finiteness of the system as well as the presence of a hard wall introduced for achieving an appropriate equilibrium ion configuration. It is also confirmed that, in the strong-coupling regime, surface properties are not much influenced by the finiteness of a system and by the presence of a hard wall.