Eur. Phys. J. B 53, 61-65 (2006)
https://doi.org/10.1140/epjb/e2006-00344-1

Liquid-liquid critical point: an analytical approach

Laboratoire de Physique Appliquée, Faculté des Sciences et Techniques de Tanger, B.P., 416 Tanger, Maroc

Corresponding author: ^a a_daanoun@yahoo.fr

Received: 25 October 2005
Revised: 30 May 2006
Published online: 6 September 2006

Abstract

Theoretical simulations and experimental studies have showed that many systems (like liquid metals) can exhibit two phase transitions: gas-liquid and liquid-liquid. Consequently the fluid phase of these systems presents two critical points, namely the usual gas-liquid (G-L) critical point and the liquid-liquid critical point that results from a phase transition between two liquids of different densities: a low density liquid (LDL) and a high density liquid (HDL). The van der Waals theory for simple fluids [Phys. Rev. E 50, 2913 (1994)] is based on taking a system with purely repulsive forces as a reference, is able to describe two stable first-order phase transitions between fluids of different densities. The particles in our system interact via a total pair potential, which splits into a repulsive V_R and a density-dependent attractive V_A part.