中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Lorenz number and transport properties of Fe: Implications to the thermal conductivity at Earth's core-mantle boundary

文献类型:期刊论文

作者Yuan Yin; Lin Wang; Shuangmeng Zhai; Yun Liu
刊名American Mineralogist
出版日期2024
卷号109期号:11页码:1850-1860
关键词Iron, First-principles Calculation, Thermal Conductivity, Earth’s Core, High Pressure, High Temperature, Physics And Chemistry Of Earth’s Deep Mantle And Core
DOI10.2138/am-2023-9246
英文摘要

The electrical resistivity (ρ) and thermal conductivity (κ) of the Earth’s core compositions are essential parameters for constraining the core’s thermal state, the inner core age, and the evolutionary history of the geodynamo. However, controversies persist between experimental and computational results regarding the electronic transport properties (ρ and κ) of the Earth’s core. Iron is the major element in the core, and its transport properties under high-pressure and high-temperature conditions are crucial for understanding the core’s thermal state. We measured the ρ values of solid iron using the four-wire van der Pauw method at 300 K and pressures of 3 to 26 GPa within a multi-anvil press. For comparison, we calculated the ρ and κ values of hexagonal close-packed (hcp) iron at 300–4100 K and 22–136 GPa using the first-principles molecular dynamics (FPMD) method. Our calculations generally align with prior studies, indicating that the electrical resistivity of solid hcp iron at Earth’s core-mantle boundary (CMB) conditions is ~76–83 μΩ∙cm. The resistivity of hcp iron changes slightly as it melts from solid to liquid at pressures from 98 to 134 GPa. The effects of temperature and pressure on the Lorenz numbers of solid hcp iron were investigated according to our calculation results and previous studies. Under the CMB’s pressure conditions, the κ of hcp iron initially decreases with increasing temperature and subsequently increases. The electron-electron scattering plays a dominant role at low temperatures and causes the decrease in κ. At high temperatures, the increase of electronic specific heat significantly increases the Lorentz number and κ. Overall, we estimate the κ of solid hcp iron at the CMB’s condition to be 114 ± 6 W/m/K, slightly lower than the room temperature value of 129 ± 9 W/m/K at the same pressure. Our model shows that a 0–525 km thickness of a thermally stratified layer may exist beneath the Earth’s CMB, depending on the core’s heat flow and thermal conductivity.

URL标识查看原文
语种英语
源URL  
专题地球化学研究所_矿床地球化学国家重点实验室
作者单位1.State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
2.Earth and Planets Laboratory, Carnegie Science, Washington, D.C. 20015, U.S.A.
3.Research Center for Planetary Science, College of Earth Sciences, Chengdu University of Technology, Chengdu 610059, China
4.Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
推荐引用方式
GB/T 7714
Yuan Yin,Lin Wang,Shuangmeng Zhai,et al. Lorenz number and transport properties of Fe: Implications to the thermal conductivity at Earth's core-mantle boundary[J]. American Mineralogist,2024,109(11):1850-1860.
APA Yuan Yin,Lin Wang,Shuangmeng Zhai,&Yun Liu.(2024).Lorenz number and transport properties of Fe: Implications to the thermal conductivity at Earth's core-mantle boundary.American Mineralogist,109(11),1850-1860.
MLA Yuan Yin,et al."Lorenz number and transport properties of Fe: Implications to the thermal conductivity at Earth's core-mantle boundary".American Mineralogist 109.11(2024):1850-1860.

入库方式: OAI收割

来源:地球化学研究所

浏览0
下载0
收藏0
其他版本

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。