Reconciliation of Experiments and Theory on Transport Properties of Iron and the Geodynamo
Reconciliation of Experiments and Theory on Transport Properties of Iron and the Geodynamo
复制标题
铁输运特性与地发电机的实验与理论的协调
DOI：
10.1103/physrevlett.125.078501
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发表时间：
2020-08-13
影响因子：
8.6
通讯作者：
Lin, Jung-Fu
中科院分区：
文献类型：
--
作者：
Zhang, Youjun;Hou, Mingqiang;Lin, Jung-Fu
我们用四探针范德堡方法结合均匀平顶激光加热在数模转换器中测量了近170 Gpa和近3000K的HCP铁的电阻率，并用包括电子-声子和电子-电子散射在内的第一性原理分子动力学计算了它的电导和热导率。我们发现，测量的HCP铁的电阻率随温度几乎呈线性增加，并与我们的计算一致。结果表明，在接近核幔边界的条件下，HCP铁的电阻率和热导率分别约为80+/-5µOmega cm和100+/-10Wm(-1)K-1。我们的结果表明，从地核流出的绝热热流类似于10+/-1TW，支持由热和成分对流驱动的今天的地球发电机。
We measure the electrical resistivity of hcp iron up to similar to 170 GPa and similar to 3000 K using a four-probe van der Pauw method coupled with homogeneous flattop laser heating in a DAC, and compute its electrical and thermal conductivity by first-principles molecular dynamics including electron-phonon and electron-electron scattering. We find that the measured resistivity of hcp iron increases almost linearly with temperature, and is consistent with our computations. The results constrain the resistivity and thermal conductivity of hcp iron to similar to 80 +/- 5 mu Omega cm and similar to 100 +/- 10 W m(-1) K-1, respectively, at conditions near the core-mantle boundary. Our results indicate an adiabatic heat flow of similar to 10 +/- 1 TW out of the core, supporting a present-day geodynamo driven by thermal and compositional convection.