Scaling Laws and Critical Properties for fcc and hcp Metals

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, and 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.

Hard-core attractive Yukawa fluid global isomorphism with the lattice gas model

“…In this respect numerical methods for calculating the grand canonical-function are of great importance because they allow to trace the dependence of thermodynamic quantities on the parameters of various interaction potentials 14,15 . The results show that equation (2) valid even for ionic liquids and liquid metals [16][17][18][19][20] .…”

Evaluation of the grand-canonical partition function using Expanded Wang-Landau simulations. V. Impact of an electric field on the thermodynamic properties and ideality contours of water

“…where V is the reciprocal density and N = N p(N ) is the average number of particles in the system. Previous work in the field has focused on establishing the shape of this contour for the Van der Waals equation 29 , model systems 91 , Argon 30 , metals 33,35,40,92 and to bottom) Tetrahedral order parameters q t (circles), alignment order parameter q l (squares) and number of hydrogen bonds N H (diamonds) for the saturated liquid in the absence of field (black)…”

“…at the vapor-liquid phase boundary, for compressed liquids as well as under supercritical conditions. In particular, in the supercritical region of the phase diagram, we focus on analyzing the effect of the field on the ideality contours [29][30][31][32][33][34][35] , known as the Zeno line and the curve of ideal enthalpy, to establish a correspondence between the results obtained for different fields. These ideality contours have recently emerged as a new way to bridge the gap in our understanding of supercritical fluids [36][37][38][39] and have paved the way for the development of new similarity laws 30 and maps of the supercritical region of the phase diagram 40,41 .…”

Similarity law and critical properties in ionic systems.

“…This equation provides a direct route to determine the critical parameters when they are difficult to access through experiments, such as e.g. for metals [8,9,10] which exhibit very high critical temperatures. Recent work based either on experimental data or on molecular simulations have started to show the usefulness of Zeno line based approaches and its validity for a wide range of systems including metals and molecular fluids [11,12,13,14,15].…”