Impact of magnetism on Fe under Earth's core conditions

Using a microscopic phenomenological model for longitudinal spin fluctuations (LSFs) based on density functional theory calculations, we demonstrate that under the Earth's core conditions (P≈360 GPa, T≈6000 K), Fe acquires substantial local magnetic moment, up to 1.3 μB, for different crystal structure modifications. We demonstrate that the LSFs produce a substantial effect on the magnetic and thermodynamic properties of iron, in particular, its equilibrium volume under solid Earth's core conditions.