Thermodynamic Geometry of two-dimensional square-well fluids

TL;DR

This study explores the thermodynamic geometry of two-dimensional square-well fluids, comparing their behavior to three-dimensional fluids in subcritical and supercritical regions, revealing differences in the validity of certain thermodynamic lines.

Contribution

It provides the first detailed comparison of thermodynamic geometric properties of 2D and 3D square-well fluids, highlighting unique behaviors in supercritical and subcritical regimes.

Findings

R-crossing method has narrower validity in 2D fluids.

Widom lines extend further into supercritical region in 2D fluids.

Clausius--Clapeyron equation validity differs between 2D and 3D fluids.

Abstract

Thermodynamic geometry of two-dimensional fluids has been investigated using a square-well model as a prototype fluid. A comparison with the three-dimensional case is performed in the subcritical and supercritical domains of thermodynamic space. In the subcritical region, it is found that the R-crossing method has a narrower range of validity for two-dimensional fluids compared to three-dimensional ones. On the other hand, in the supercritical region, an analysis of different Widom lines, including the R Widom line, shows that for two-dimensional fluids these lines extend further into the supercritical region than their three-dimensional counterparts. A similar behavior is observed for the validity of the Clausius--Clapeyron equation in two-dimensional fluids.