# First-order phase transition in the framework of the cell fluid model: Regions of chemical potential variation and the corresponding densities

## TL;DR

This paper provides a microscopic analysis of the fluid system near its critical point, deriving equations for the binodal curve and analyzing chemical potential and density variations for temperatures below the critical temperature.

## Contribution

It introduces a microscopic description of the cell fluid model near the critical point, including equations for the binodal curve in the critical neighborhood.

## Key findings

- Derived the equation of state using Heaviside functions.
- Identified regions of chemical potential and density variations.
- Obtained the binodal curve equation near the critical point.

## Abstract

A microscopic description is given for the behavior of the fluid system in an immediate vicinity of its critical point, where theoretical and experimental researches are difficult to carry out. For the temperatures $T<T_c$, the regions of chemical potential and density variations are singled out and analyzed. The equation of state of the cell fluid model in terms of temperature-chemical potential is written using the Heaviside functions. This equation is also given in terms of the temperature and density variables. As a result of the study of the relationship between the density and the chemical potential, an equation for the binodal curve is obtained in a narrow neighborhood of the critical point.