The Earth's core is composed of iron,nickel,and a small amount of light elements(e.g.,Si,S,O,C,N,H and P).The thermal conductivities of these components dominate the adiabatic heat flow in the core,which is highly correlated to geodynamo.Here we review a large number of studies on the electrical and thermal conduc-tivity of iron and iron alloys and discuss their implications on the thermal evolution of the Earth's core.In summary,we suggest that the Wiedemann-Franz law,commonly used to convert the electrical resistivity to thermal con-ductivity for metals and alloys,should be cautiously applied under extremely high pressure-temperature(P-T)conditions(e.g.,Earth's core)because the Lorentz number may be P-T dependent.To date,the discrepancy in the thermal conductivity of iron and iron alloys remains between those from the resistivity measurements and the thermal diffusivity modeling,where the former is sys-tematically larger.Recent studies reconcile the electrical resistivity by first-principles calculation and direct mea-surements,and this is a good start in resolving this discrepancy.Due to an overall higher thermal conductivity than previously thought,the inner core age is presently constrained at～1.0 Ga.However,light elements in the core would likely lower the thermal conductivity and pro-long the crystallization of the inner core.Meanwhile,whe-ther thermal convection can power the dynamo before the inner core formation depends on the amounts of the proper light elements in the core.More works are needed to establish the thermal evolution model of the core.

Yuan Yin;Qingwen Zhang;Youjun Zhang;Shuangmeng Zhai;Yun Liu

State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;International Research Center for Planetary Science,College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China;Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065,China;Key Laboratory of High-Temperature and High-Pressure Study of the Earth's Interior,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China

地球化学学报（英文版）

[1]Yuan Yin;Qingwen Zhang;Youjun Zhang;Shuangmeng Zhai;Yun Liu-.Electrical and thermal conductivity of Earth's core and its thermal evolution—A review)[J].地球化学学报（英文版）,2022(04):665-688

geodynamo,whe

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