Eur. Phys. J. E 1, 67-73
One and two-component hard-core plasmas
R.R. Netz1 - H. Orland2
1 Max-Planck-Institut für Kolloid-und Grenzflächenforschung, Am Mühlenberg, 14424
2 Service de Physique Théorique, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
Received 16 February 1999 and Received in final form 19 July 1999
A field theory is presented for particles which interact via Coulomb and hard-core potentials, as relevant for classical plasmas, electrolytes, and charged colloidal solutions. We apply the method to the one-component plasma with hard cores (OCPHC), consisting of identical particles of fixed charge and diameter in a neutralizing background, and the symmetric two-component plasma with hard cores (TCPHC), consisting of equal numbers of positively and negatively charged particles of identical size. We obtain the first few coefficients of a systematic low-density expansion of the free energy for both models exactly and in closed form. The OCPHC coefficients go over to the classical Abe result in the high-charge (or small hard-core diameter) limit. The TCPHC, on the other hand, exhibits diverging coefficients in the high-charge limit, which is due to the formation of strongly bound ion-pairs.
82.70.-y Disperse systems - 52.25.-b Plasma properties - 61.20.Qg Structure of associated liquids: electrolytes, molten salts, etc.
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