Thermal conductivity of Fe-Si alloys and thermal stratification in Earth's core

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23640%2F21%3A43964072" target="_blank" >RIV/49777513:23640/21:43964072 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1073/pnas.2119001119" target="_blank" >https://doi.org/10.1073/pnas.2119001119</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1073/pnas.2119001119" target="_blank" >10.1073/pnas.2119001119</a>

Result language

angličtina

Original language name

Thermal conductivity of Fe-Si alloys and thermal stratification in Earth's core

Original language description

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., &gt; 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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

<a href="/en/project/EF15_003%2F0000358" target="_blank" >EF15_003/0000358: Computational and Experimental Design of Advanced Materials with New Functionalities</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

ISSN

0027-8424

e-ISSN

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Volume of the periodical

119

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

8

Pages from-to

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UT code for WoS article

000748065500006

EID of the result in the Scopus database

2-s2.0-85122700628