Název:	Thermal conductivity of Fe-Si alloys and thermal stratification in Earth's core
Autoři:	Zhang, Youjun Luo, Kai Hou, Mingqiang Driscoll, Peter Salke, Nilesh P. Minár, Jan Prakapenka, Vitali B. Greenberg, Eran Hemley, Russell J. Cohen, R. E. Lin, Jung-Fu
Citace zdrojového dokumentu:	ZHANG, Y. LUO, K. HOU, M. DRISCOLL, P. SALKE, NP. MINÁR, J. PRAKAPENKA, VB. GREENBERG, E. HEMLEY, RJ. COHEN, RE. LIN, J. Thermal conductivity of Fe-Si alloys and thermal stratification in Earth's core. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2021, roč. 119, č. 1, s. nestránkováno. ISSN: 0027-8424
Datum vydání:	2021
Nakladatel:	National Academy of Sciences
Typ dokumentu:	článek article
URI:	2-s2.0-85122700628 http://hdl.handle.net/11025/47054
ISSN:	0027-8424
Klíčová slova v dalším jazyce:	diamond anvil cell;Earth’s core;geodynamo;light elements;thermal conductivity
Abstrakt v dalším jazyce:	Light elements in Earth’s core play a key role in driving convection and influencing geodynamics, both of which are crucial to the geodynamo. However, the thermal transport properties of iron alloys at high-pressure and -temperature conditions remain uncertain. Here we investigate the transport properties of solid hexagonal close-packed and liquid Fe-Si alloys with 4.3 and 9.0 wt % Si at high pressure and temperature using laser-heated diamond anvil cell experiments and first-principles molecular dynamics and dynamical mean field theory calculations. In contrast to the case of Fe, Si impurity scattering gradually dominates the total scattering in Fe-Si alloys with increasing Si concentration, leading to temperature independence of the resistivity and less electron–electron contribution to the conductivity in Fe-9Si. Our results show a thermal conductivity of ∼100 to 110 Wm21K21 for liquid Fe-9Si near the topmost outer core. If Earth’s core consists of a large amount of silicon (e.g., > 4.3 wt %) with such a high thermal conductivity, a subadiabatic heat flow across the core–mantle boundary is likely, leaving a 400- to 500-km-deep thermally stratified layer below the core–mantle boundary, and challenges proposed thermal convection in Fe-Si liquid outer core. © 2022 National Academy of Sciences. All rights reserved.
Práva:	© National Academy of Sciences
Vyskytuje se v kolekcích:	Články / Articles (RAM) OBD

Všechny záznamy v DSpace jsou chráněny autorskými právy, všechna práva vyhrazena.