Scaling Laws and Critical Properties for $FCC$ and $HCP$ Metals

TL;DR

This paper uses advanced simulation methods to determine critical properties of FCC and HCP metals, revealing new scaling laws for vaporization enthalpy and entropy with specific critical exponents.

Contribution

It introduces a novel application of the Expanded Wang-Landau method to evaluate critical parameters of metals with many-body interactions, and proposes new scaling laws for vaporization properties.

Findings

Critical properties of 11 FCC and HCP metals calculated.

New scaling laws for vaporization enthalpy and entropy proposed.

Abstract

The determination of the critical parameters of metals has remained particularly challenging both experimentally, because of the very large temperatures involved, and theoretically, because of the many-body interactions that take place in metals. Moreover, experiments have shown that these systems exhibit an unusually strong asymmetry of their binodal. Recent theoretical work has led to new similarity laws, based on the calculation of the Zeno line and of the underlying Boyle parameters, which provided results for the critical properties of atomic and molecular systems in excellent agreement with experiments. Using the recently developed Expanded Wang-Landau (EWL) simulation method, we evaluate the grand-canonical partition function, over a wide range of conditions, for $11$ $FCC$ and $HCP$ metals ($Ag$, $Al$, $Au$, $Be$, $Cu$, $Ir$, $Ni$, $Pb$, $Pd$, $Pt$ and $Rh$), modeled with a many-body interaction potential. This allows us to calculate the binodal, Zeno line, Boyle parameters and, in turn, obtain the critical properties for these systems. We also propose two scaling laws for the enthalpy and entropy of vaporization, and identify critical exponents of $0.4$ and $1.22$ for these two laws, respectively.