Phase Behavior of a Cell Fluid Model with Modified Morse Potential

Abstract

The present article gives a theoretical description of a first-order phase transition in the cell fluid model with a modified Morse potential and an additional repulsive interaction. In the framework of the grand canonical ensemble, the equation of state of the system in terms of chemical potential–temperature and terms of density–temperature is calculated for a wide range of the density and temperature. The behavior of the chemical potential as a function of the temperature and density is investigated. The maximum and minimum admissible values of the chemical potential, which approach each other with decreasing the temperature, are exhibited. The existence of a liquid-gas phase transition in a limited temperature range below the critical Tc is established.