Electrical and thermal transport properties of iron and iron‐silicon alloy at high pressure
Electrical and thermal transport properties of iron and iron‐silicon alloy at high pressure
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DOI：
10.1002/2013gl057930
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发表时间：
2012-10
影响因子：
5.2
通讯作者：
C. Seagle;E. Cottrell;Y. Fei;D. Hummer;V. Prakapenka
中科院分区：
文献类型：
--
作者：
C. Seagle;E. Cottrell;Y. Fei;D. Hummer;V. Prakapenka
地球核心的热传导效率控制着对流的动力学，并限制了地球发电机的可用功率。我们已经测量了铁和铁硅合金的室温电阻率到60 GPa，并提出了一个新的模型，在高压和高温下的电阻率与地球的核心。该模型与现有的冲击波数据和理论研究进行了比较。对于电阻率的幂律和线性温度依赖性，计算的核幔边界处的热导率对于纯铁为~67-145 W/m/K，对于Fe-9 wt % Si为~41-60 W/m/K。堆芯中的杂质对铁的输运性质有很大的影响，这可能会对堆芯热模型产生重大影响。描述数据的模型表明，在核心压力下的热导率比以前提出的更高，需要额外的能源在过去操作的地球发电机。
The efficiency of heat transfer by conduction in the Earth's core controls the dynamics of convection and limits the power available for the geodynamo. We have measured the room temperature electrical resistivity of iron and iron‐silicon alloy to 60 GPa and present a new model of the resistivity at high pressures and temperatures relevant to the Earth's core. The model is compared with available shock wave data and theoretical studies. For a power law and linear temperature dependence of electrical resistivity, the calculated thermal conductivity at the core‐mantle boundary is ~67–145 W/m/K for pure Fe and ~41–60 W/m/K for Fe–9 wt % Si. Impurities in the core have a strong effect on the transport properties of iron that could significantly impact core thermal models. The models describing the data indicate higher thermal conductivity at core pressure than previously suggested, requiring additional energy sources in the past to operate the geodynamo.