Alloy disorder and fluctuating magnetic moments in the Earth's core

0521048 - FZÚ 2020 RIV NL eng J - Journal Article
Drchal, Václav - Kudrnovský, Josef - Wagenknecht, D. - Turek, I.
Alloy disorder and fluctuating magnetic moments in the Earth's core.
Journal of Magnetism and Magnetic Materials. Roč. 475, Apr (2019), s. 767-771. ISSN 0304-8853. E-ISSN 1873-4766
R&D Projects: GA ČR GA18-07172S
Institutional support: RVO:68378271
Keywords : Earth's core * iron alloys * fluctuating moments * spin-disorder resistivity
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.717, year: 2019
Method of publishing: Limited access
https://doi.org/10.1016/j.jmmm.2018.11.112

The electronic and thermal transport properties of the Earth’s core are crucial for many geophysical models. We show by first-principles modeling and methods of statistical physics that the spin disorder, not considered in previous studies, gives an essential contribution to the electrical resistivity at the Earth’s core conditions. The origin of this spin-disorder resistivity (SDR) consists in the existence of fluctuating local moments that are stabilized at high temperatures by the magnetic entropy even at pressures at which the ground state of iron is non-magnetic. It turns out that the contributions of various scattering mechanisms (alloy disorder, phonon scattering, spin disorder, and electron-electron correlations) are comparable, but not additive. Here we report results for iron and iron-rich alloys (Fe-O, Fe-Si, Fe-S) that can be present in the Earth’s core. Special attention is paid to alloys with two magnetic elements (Fe-Ni).
Permanent Link: http://hdl.handle.net/11104/0305705