An Experimental Examination of Thermal Conductivity Anisotropy in hcp Iron

Frontiers in Earth Science

卷:6

Kei Hirose¹  Yuki Sato²  Kenji Ohta²  Yu Nishihara⁴  Saori I. Kawaguchi⁵  Naohisa Hirao⁵  Yasuo Ohishi⁵  Takashi Yagi⁶ 

[1] Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan;

[2] Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo, Japan;

[3] Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan;

[4] Geodynamics Research Center, Ehime University, Ehime, Japan;

[5] Japan Synchrotron Radiation Research Institute, Hyogo, Japan;

[6] National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan;

关键词: hcp iron;    Earth's core;    thermal conductivity;    XRD;    thermoreflectance (TR);    diamond anvil cell (DAC);   

DOI  :  10.3389/feart.2018.00176

来源: DOAJ

【 摘 要 】

The Earth's core mainly consists of iron, and its thermal transport properties are of vital importance for our understanding of the thermal evolution and the dynamics of the core and the mantle. However, the reported values of thermal conductivity of iron at the core conditions are so far inconclusive. Although hexagonal closed-packed (hcp) iron is often studied as a proxy metal to investigate the physical properties not only of the inner core, but also the outer core, the anisotropy of the thermal conductivity of hcp iron has never been experimentally examined. Here we report the results of texture analyses by means of synchrotron X-ray diffraction experiments and thermal conductivity measurements on polycrystalline hcp iron up to 44.5 GPa and 300 K. These results indicate that the thermal conductivity of single crystal hcp iron along c axis is about 3–4 times higher than that along a axis, which could have partially caused the controversial values of the thermal conductivity of hcp iron at the Earth's core conditions.

【 授权许可】

Unknown