Sulfur Partitioning between Solid and Liquid Iron at High Pressure

高压下固态铁和液态铁之间的硫分配

• 批准号: 1144422
• 负责人: Yingwei Fei
• 金额: $ 37.99万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1144422&HistoricalAwards=false
• 关键词: Sulfur; Partitioning; between; Solid; Liquid

Sulfur Partitioning between Solid and Liquid Iron at High PressureIntellectual Merit. The Fe-FeS system, with eutectic melting behavior and preferential S partitioning to liquid iron, has been used as a model system to explain the basic observations of the Earth?s core system, including the liquid outer core and solid inner core configuration and the large density jump at the inner core boundary (ICB). In order to evaluate the role of S during the core formation and evolution of the core, full knowledge of the phase relations in the Fe-FeS system as a function of pressure up to core pressures is needed. It is proposed to determine the melting relations in the Fe-FeS system up to 30 GPa in the multi-anvil apparatus and to extend the measurements up to at least 140 GPa in high-temperature diamond-anvil cell using combination of in-situ observations and ex-situ characterization with FIB/SEM crossbeam. A thermodynamic model will be developed to reproduce the experimental data, and used to extrapolate the experimentally determined phase relations in the Fe-FeS system to ICB conditions. Emphasis is placed on obtaining reliable, high-quality data through innovative experimental design and development of quantitative analysis with high spatial resolution. Although designed for proposed work on the Fe-FeS binary system, the techniques developed here will open a new class of experiments that can be applied to other systems in the future (e.g., to investigate the roles of other light elements, such as Si and O, in the Earth?s core). The thermodynamic model will be used to evaluate the S contribution to the density jump at the ICB by calculating the S partitioning between solid and liquid iron and its effect on the density change. The calculated melting temperature as a function of the S content will serve as a reference point for other multi-component Earth?s core models.Broad Impacts. The proposed research will open new research directions in experimental petrology. It addresses a broad issue in deep Earth study at the interface of petrology, mineral physics, geochemistry, and geophysics. The experimental techniques and procedures developed through this research will be available to the community. The PI will continue to involve and train graduate students and postdoctoral associates in the proposed research and provide them with broad, competitive research experience. Research results will be disseminated primarily through publications in scientific journals, participation at scientific conferences, and occasionally through public news media. The proposed projects will produce high-quality data that are necessary for understanding the interior of the Earth and developing new frontiers for cutting-edge research. The expected results will have broad impact in many different fields including experimental petrology, geochemistry, geophysics, mineral physics, and geodynamics.

在高压智能优点处固体和液态铁之间的硫分配。 Fe-FES系统具有共晶熔融行为和对液态铁的优先S分配，已被用作模型系统，以解释地球核心系统的基本观察结果，包括液体外核和固体内部核心构型和内核边界（ICB）的较大密度跳跃。为了评估S在核心核心形成和核心演变中的作用，需要对FE-FES系统中的相位关系的全部了解，这是压力到核心压力的函数。 提议在多动仪器中确定最高30 GPA的Fe-FES系统中的熔融关系，并通过使用固醇观测值和fib/sem sem crossbeam的situ观测和静脉表征的组合，将测量值扩展到至少140 GPA至至少140 GPA。将开发热力学模型来重现实验数据，并用于推断Fe-Fes系统中实验确定的相位关系到ICB条件。重点是通过具有高空间分辨率的定量分析的创新实验设计和开发来获得可靠的高质量数据。尽管为FE-FES二进制系统提供了建议的工作，但此处开发的技术将打开新的实验类别，这些实验可以在将来应用于其他系统（例如，研究其他光元在地球核心中的其他光元的作用）。热力学模型将通过计算固体和液态铁之间的S分配及其对密度变化的影响来评估S对ICB密度跳跃的S贡献。计算出的熔化温度随S含量的函数将作为其他多组分地球核心模型的参考点。拟议的研究将开放实验性岩石学的新研究方向。它解决了深层研究岩石学，矿物质物理学，地球化学和地球物理界面的广泛问题。通过这项研究开发的实验技术和程序将提供给社区。 PI将继续参与并培训研究生和博士后同伴参与拟议的研究，并为他们提供广泛的竞争研究经验。研究结果将主要通过科学期刊中的出版物，科学会议的参与以及偶尔通过公共新闻媒体传播。拟议的项目将产生高质量的数据，这些数据是理解地球内部和开发新的前沿研究领域所必需的。预期的结果将在许多不同领域都产生广泛的影响，包括实验性岩石学，地球化学，地球物理学，矿物质物理学和地球动力学。