Electronic properties and magnetism of iron at the Earth's inner core conditions

Abstract

We employ state-of-the-art ab initio simulations within the dynamical mean-field theory to study three likely phases of iron (hexogonal close-packed, hcp, face centered cubic, fcc, and body centered cubic, bcc) at the Earth's core conditions. We demonstrate that the correction to the electronic free energy due to correlations can be significant for the relative stability of the phases. The strongest effect is observed in bcc Fe, which shows a non-Fermi liquid behaviour, and where a Curie-Weiss behaviour of the uniform susceptbility hints at a local magnetic moment still existing at 5800 K and 300 GPa. We predict that all three structures have sufficiently high magnetic susceptibility to stabilize the geodynamo.

7 pages, 6 figures. Changes in version 2: the magnetic susceptibility has been recalculated for a larger temperature range and with a higher accuracy (Fig. 4), comparison with the enhanced Stoner model added, some other minor correction to the text

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Cited by in corpus (4)

• Local magnetic moments in iron and nickel at ambient and Earth's core conditions
• Magnetic exchange in $\alpha$-iron from the ab initio calculations in the paramagnetic phase
• Electronic correlations in Fe at Earth's inner core conditions: effect of doping with Ni
• Quantum-Many-Body Intermetallics: Phase Stability of Fe${}_3$Al and Small-Gap Formation in Fe${}_2$VAl