Open AccessThermal conductivity of Fe-Si alloys and thermal stratification in Earth’s core
Author(s) -
Youjun Zhang,
Kai Luo,
Mingcai Hou,
Peter Driscoll,
Nilesh P. Salke,
J. Minář,
Vitali B. Prakapenka,
Eran Greenberg,
Russell J. Hemley,
R. E. Cohen,
JungFu Lin
Publication year - 2021
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2119001119
Subject(s) - thermal conductivity , inner core , materials science , diamond anvil cell , silicon , outer core , thermal conduction , convection , condensed matter physics , thermodynamics , metallurgy , composite material , physics , high pressure
Significance Earth’s liquid outer core is mainly composed of iron alloyed with ∼8 to 10% of light elements (e.g., silicon). Convection of the liquid core generates Earth’s magnetic field, which is controlled by the thermal conductivity of the core. In this study, we investigated the resistivity and thermal conductivity of iron-silicon alloys as a candidate composition in Earth’s core via high-pressure and -temperature experiments and numerical calculations. We found a near temperature independence of the resistivity in iron-silicon alloys at Earth core’s pressure and thus a high thermal conductivity. This work indicates that if silicon is the sole major light element in Earth’s core it could depress thermal convection and promote a thermally stratified layer at the topmost outer core.