Properties of Liquid Iron along the Melting Line up to the Earth-core Pressures

TL;DR

This study uses molecular dynamics to analyze the transport properties and shear modulus of liquid iron under extreme conditions relevant to Earth's core, revealing viscosity behavior and vitrification potential.

Contribution

It provides new insights into the transport coefficients and shear modulus of liquid iron at high pressures and temperatures along the melting line.

Findings

Viscosity and diffusion coefficient increase along the melting line.

Liquid iron behaves similarly to soft spheres with exponent n=4.6 at high T and P.

Potential vitrification of liquid iron under Earth-core conditions.

Abstract

We report a molecular dynamics study of transport coefficients and infinite frequency shear mod- ulus of liquid iron at high temperatures and high pressures. We observe a simultaneous rise of both shear viscosity and diffusion coefficient along the melting line and estimate if liquid iron can vitrify under Earth-core conditions. We show that in frames of the model studied in our work iron demonstrates a moderate increase of viscosity along the melting line. It is also demonstrated that in the limit of high temperatures and high pressures the liquid iron behaves similar to the soft spheres system with exponent n=4.6.