Freezing of Simple Liquid Metals

TL;DR

This paper investigates the freezing behavior of simple liquid metals and compares the stability of different crystalline structures using thermodynamic perturbation theory and effective pair potentials, providing insights into phase transitions.

Contribution

It introduces a method combining thermodynamic perturbation theory and classical density-functional theory to predict freezing transitions and stability of crystalline phases in liquid metals.

Findings

Predicted freezing transitions for Na, Mg, and Al.

Calculated free energy differences favoring certain crystal structures.

Qualitative agreement with experimental data.

Abstract

Freezing of simple liquid metals and the relative stabilities of competing crystalline solids are investigated using thermodynamic perturbation theory, the interactions between ions being modeled by effective pair potentials derived from pseudopotential theory. The ionic free energy of the solid phase is calculated, to first order in the perturbation potential, using classical density-functional theory and an accurate approximation to the hard-sphere radial distribution function. Free energy calculations for Na, Mg, and Al yield well-defined freezing transitions and structural free energy differences for bcc, fcc, and hcp crystals in qualitative agreement with experiment.