Transport Properties of Fe-X (X = C, S, O, H) at extreme conditions

The transport properties of iron alloys with light elements such as carbon, sulfur, oxygen, and hydrogen are important factors for the heat transport of Earth’s and other planetary cores. In this study, we computed the electrical resistivity and thermal conductivity for hcp iron and iron alloys with Density Functional Theory (DFT) up to and beyond Earth core pressures and temperatures. We have used Korringa-Kohn-Rostoker (SPR-KKR) with a coherent potential approximation (CPA) for both compositional scattering and phonon scattering within a Debye model. We have compared with experiments and with scattering from disordered supercells and first-principles molecular dynamics and find good agreement for Fe-Si. We find that electrical resistivity has a strong negative slope with temperature from impurity scattering, whereas phonon scattering gives a positive slope.