State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK.
Nat Chem. 2014 Jul;6(7):644-8. doi: 10.1038/nchem.1925. Epub 2014 Apr 20.
Studies of the Earth's atmosphere have shown that more than 90% of the expected amount of Xe is depleted, a finding often referred to as the 'missing Xe paradox'. Although several models for a Xe reservoir have been proposed, whether the missing Xe could be contained in the Earth's inner core has not yet been answered. The key to addressing this issue lies in the reactivity of Xe with Fe/Ni, the main constituents of the Earth's core. Here, we predict, through first-principles calculations and unbiased structure searching techniques, a chemical reaction of Xe with Fe/Ni at the temperatures and pressures found in the Earth's core. We find that, under these conditions, Xe and Fe/Ni can form intermetallic compounds, of which XeFe3 and XeNi3 are energetically the most stable. This shows that the Earth's inner core is a natural reservoir for Xe storage and provides a solution to the missing Xe paradox.
对地球大气的研究表明，预期的氙气含量中有 90%以上已经耗尽，这一发现通常被称为“缺失的氙气悖论”。尽管已经提出了几种氙气储存库模型，但尚未回答缺失的氙气是否可以包含在地球的地核中。解决这个问题的关键在于氙气与铁/镍（地核的主要成分）的反应性。在这里，我们通过第一性原理计算和无偏结构搜索技术预测，在地球核心中发现的温度和压力下，氙气与铁/镍之间会发生化学反应。我们发现，在这些条件下，氙气和铁/镍可以形成金属间化合物，其中 XeFe3 和 XeNi3 在能量上是最稳定的。这表明地球的地核是氙气储存的天然储库，为解决缺失的氙气悖论提供了一种解决方案。
