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Updated: May 11, 2026

Simulation of the Planetary Interior Differentiation Processes in the Laboratory
Published on: November 15, 2013
Melting of iron at Earth's inner core boundary based on fast X-ray diffraction
S Anzellini1, A Dewaele, M Mezouar
1Commissariat à l'Énergie Atomique, Direction des Applications Militaires, Île de France, Arpajon Cedex, France. simone.anzellini@cea.fr
Abstract:
Earth's core is structured in a solid inner core, mainly composed of iron, and a liquid outer core. The temperature at the inner core boundary is expected to be close to the melting point of iron at 330 gigapascal (GPa). Despite intensive experimental and theoretical efforts, there is little consensus on the melting behavior of iron at these extreme pressures and temperatures. We present static laser-heated diamond anvil cell experiments up to 200 GPa using synchrotron-based fast x-ray diffraction as a primary melting diagnostic. When extrapolating to higher pressures, we conclude that the melting temperature of iron at the inner core boundary is 6230 ± 500 kelvin. This estimation favors a high heat flux at the core-mantle boundary with a possible partial melting of the mantle.
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