Exploring Thermal Conductivity of h.c.p. Iron (ε-Fe) at the Earth’s Core Conditions from Direct ab initio Molecular Dynamics Simulations

The exact value of electronic thermal conductivity (κ_el) of ε-Fe under the extreme pressure and temperature conditions still remains poorly known both experimentally and theoretically. Previous experiments reported quite scattered results of κ_el of ε-Fe, which could differ by several folders. By utilizing our newly developed methodology based on direct non-equilibrium ab initio molecular dynamics (NEAIMD) simulation coupled with the concept of electrostatic potential oscillation (EPO), we evaluate the electronic thermal conductivity of iron in h.c.p phase without any artificial manipulation of computational parameters. Unlike the previous theoretical studies, our methodology inherently includes all possible interactions and scattering of electrons under extreme conditions. The results of electronic thermal conductivity of iron in the Earth’s core are consistent with some previous theoretical and experimental results. More importantly, our study provides a totally new physical picture of heat transfer process in iron at Earth's core conditions from the electrostatic potential oscillation point of view. This simulation methodology offers a new approach to study thermal transport property of pure metals in planet's cores with different temperature and pressures.