Light elements in the core of a habitable Earth

关于我们星球的形成以及它如何变得适合居住的重要信息可能隐藏在我们脚下的地球深处，即核心。轻元素（特别是C、Si、O或S）的性质和丰度与行星的形成和地球发电机密切相关，地球发电机保护地球表面的生命免受太阳风的破坏性影响，是理解地球大气演变的关键参数。关于铁与潜在轻元素的合金和化合物在地核条件下（数兆巴压力和超过3000 K的温度）的系统实验数据要么是有限的，不一致的，或没有。本项目的目标是利用新型的激光加热金刚石对顶砧单晶X射线衍射技术研究Fe-L（L=Si，O，S，C）二元体系中各相的相关系和热弹性性质。我们将获得了解地球的化学分化包含一个金属核心，模拟过去和现在的历史核心，以及核心形成对可居住行星的发展的影响至关重要的信息。特别注意将集中在以下化合物的研究：FeO，Fe 3C，Fe 7 C3，Fe 3S，Fe 2S，FeS，Fe 3Si和FeSi。除了X射线衍射方法外，还将通过多种互补技术（穆斯堡尔、拉曼和红外光谱、TEM、SEM、微探针分析等）对样品进行研究。

Important information about the formation of our planet and how it became habitable may be hidden under our feet in the deep Earth, namely in the core. The nature and abundance of light elements (particularly C, Si, O or S) are closely related to planet formation and the geodynamo that protects life on the Earth s surface from the destructive effects of the solar wind, and are crucial parameters in understanding the evolution of the Earth s atmosphere. Systematic experimental data on alloys and compounds of iron with potential light element(s) at Earth s core conditions (multi-megabar pressures and temperatures over 3000 K) are either limited, inconsistent, or absent. The goal of the project is to study the phase relations and thermoelastic properties of phases in the binary Fe-L (L=Si, O, S, C) systems using novel in situ single crystal X-ray diffraction in laser heated diamond anvil cells. We will obtain information crucial for understanding the chemical differentiation of the Earth to contain a metal core, modelling the past and present history of the core, and the effect of core formation on the development of a habitable planet. Special attention will be focused on investigations of the following compounds: FeO, Fe3C, Fe7C3, Fe3S, Fe2S, FeS, Fe3Si, and FeSi. In addition to X-ray diffraction methods, samples will be studied by multiple complementary techniques (Moessbauer, Raman and infrared spectroscopies, TEM, SEM, microprobe analysis, etc.).