Search

Thermal conductivity (k) of iron is measured up to about 134 ​GPa. The measurements are carried out using the single sided laser heated diamond anvil cell, where the power absorbed by a Fe metal foil at hotspot is calculated using a novel thermodynamical method. Thermal conductivity of fcc (γ) ​− ​ Fe increases up to a pressure of about 46 ​GPa. We find thermal conductivity values in the range of 70–80 Wm−1K−1 (with an uncertainty of 40%), almost constant with pressure, in the hcp (ε) phase of Fe. We attribute the pressure independent k above 46 ​GPa to the strong electronic correlation effects driven by the electronic topological transition (ETT). We predict a value of thermal conductivity of ε - Fe of about 40 ​± ​16 Wm−1K−1 ​at the outer core of Earth. Image 1 • Direct measurements of thermal conductivity in a laser-heated diamond cell are presented. • Thermal conductivity during melting and close to outer core condition of iron is carried out. • 25–30% decrease of thermal conductivity is observed during melting at hotspot. • Moderate value of thermal conductivity supports an old core. [ABSTRACT FROM AUTHOR]