Body-centered cubic iron-nickel alloy in Earth's core
Body-centered cubic iron-nickel alloy in Earth's core
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DOI：
10.1126/science.1142105
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发表时间：
2007-06-29
期刊：
影响因子：
56.9
通讯作者：
Abrikosov, I. A.
中科院分区：
文献类型：
--
作者：
Dubrovinsky, L.;Dubrovinskaia, N.;Abrikosov, I. A.
宇宙化学、地球化学和地球物理研究提供的证据表明，地核含有大量（5%至15%）的铁和镍。用角色散x射线衍射法在内热金刚石砧细胞（DACs）中原位研究了铁镍合金Fe0.9Ni0.1，并测量了其电阻随压力和温度的变化规律。当压力大于225千兆帕斯卡，温度大于3400开尔文时，Fe0.9Ni0.1呈体心立方结构。我们的实验和理论结果不仅支持对纯铁的冲击波数据的解释，表明固体-固体相变超过200千兆帕斯卡，而且还表明具有地球化学合理成分（即含有大量镍，硫或硅）的铁合金采用了地球内核的bcc结构。
Cosmochemical, geochemical, and geophysical studies provide evidence that Earth's core contains iron with substantial (5 to 15%) amounts of nickel. The iron-nickel alloy Fe0.9Ni0.1 has been studied in situ by means of angle-dispersive x-ray diffraction in internally heated diamond anvil cells (DACs), and its resistance has been measured as a function of pressure and temperature. At pressures above 225 gigapascals and temperatures over 3400 kelvin, Fe0.9Ni0.1 adopts a body-centered cubic structure. Our experimental and theoretical results not only support the interpretation of shockwave data on pure iron as showing a solid-solid phase transition above about 200 gigapascals but also suggest that iron alloys with geochemically reasonable compositions (that is, with substantial nickel, sulfur, or silicon content) adopt the bcc structure in Earth's inner core.