Fluid phases of argon

TL;DR

This paper presents a phase diagram of argon showing three fluid phases—liquid, supercritical mesophase, and gas—based on experimental data and Lennard-Jones simulations, highlighting percolation transitions and critical states.

Contribution

It introduces a detailed phase diagram of argon with percolation transition loci, combining experimental and simulation data to identify fluid phases and critical points.

Findings

Identification of three distinct fluid phases in argon.

Percolation transition loci define phase boundaries.

Critical density states occur at percolation locus intersections.

Abstract

A phase diagram of argon based upon percolation transition loci determined from literature experimental density-pressure isotherms, and simulation values using a Lennard-Jones model shows three fluid phases. The liquid phase spans all temperatures, from a metastable amorphous ground state at 0K, to ultra-high T. There is a supercritical mesophase bounded by two 2nd-order percolation transition loci, and a gas phase. Intersection of two percolation loci in the p-T plane thermodynamically defines an equilibrium line of critical density states.