Physics and Chemistry of Planetary Materials under Extreme Pressure and Temperature Conditions

极端压力和温度条件下行星材料的物理和化学

• 批准号: RGPIN-2019-06818
• 负责人: Shieh, Sean
• 金额: $ 2.19万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738298
• 关键词: Physics; Chemistry; Planetary; Materials; under

The objective of my research is to improve our abilities to understand the deep interior dynamics and evolution of Earth and other planets. The dynamics and evolution of Earth's and planetary interiors will influence the outermost features of the Earth and other planets. However, their interiors are inaccessible and cannot be directly investigated. Alternative approaches are to study Earth and planetary materials at simulated environments that are similar to Earth and planetary interiors. Importantly, behavior of materials at ambient conditions (1 atm and 25 C) is different from what they exhibit at greater depths. Therefore, only those data collected at pressure (P) and temperature (T) conditions corresponding to the certain depths are valid for modeling the structure and dynamics of the Earth's and planetary interiors. Therefore, study of Earth and planetary materials at P-T conditions corresponding to their deep interiors provide a promising approach to understand the dynamics and evolution of Earth's and planetary interiors. My research program uses a diamond-anvil cell (DAC, able to generate P to 3,000,000 atm) together with resistive and laser heating methods (able to heat the sample to 300-4000 K), to study planetary materials under extreme P-T conditions. The extensive P-T ranges (1-3,000,000 atm and 300-4000 K) allow us to replicate the conditions found within the Earth and planetary interiors. Moreover, using a custom-built micro-Raman system and synchrotron X-ray spectroscopy, the spectroscopic properties of relevant materials are also examined. In this proposal, we synthesize the important deep mantle phases (e.g. N-bearing silicates and iron nitrides, spinels, Zr-bearing silicates and oxide) and characterize them using synchrotron x-ray diffraction, x-ray spectroscopy, Raman and Brillouin scattering to understand their structures and physical properties (e.g. density, volume, elasticity, strength, sound velocity). The synthesized samples when quenched to ambient conditions will be examined by electron probe microanalysis and scanning electron microscopy for understanding the partitioning of the elements and element distributions within the samples, the melting criteria of the iron nitrides, and the crystal structures of the nano-scale phases. Our goals are (1) to evaluate the budgets of the N inside the Earth and other planetary interiors which is important for future planet explorations, (2) to understand the causes and mechanism of seismic anomalies (e.g. ultralow velocity) in deep Earth, (3) to evaluate the chromite spinel polymorphs at high P-T conditions and its connection to the shocked meteorites, and (4) to study strength of popular planetary ice (CO2, N2, CH4, NH3) that can be applied to modeling the dynamics of the planetary interiors. HQP will receive extensive training in high P-T mineral physics that will provide transferable skills to prepare them for employment in academic, government and private sectors.

我研究的目的是提高我们了解地球和其他行星的深层内部动力学和演化的能力。地球和行星内部的动力学和演化将影响地球和其他行星的最外层特征。然而，它们的内部是无法进入的，无法直接研究。另一种方法是在类似于地球和行星内部的模拟环境中研究地球和行星材料。重要的是，材料在环境条件（1 个大气压和 25°C）下的行为与其在更深处表现出的行为不同。因此，只有在对应于特定深度的压力 (P) 和温度 (T) 条件下收集的数据才可用于模拟地球和行星内部的结构和动力学。因此，在与其深层内部相对应的 P-T 条件下研究地球和行星材料，为了解地球和行星内部的动力学和演化提供了一种有前途的方法。 我的研究项目使用金刚石砧池（DAC，能够产生高达 3,000,000 atm 的 P）以及电阻和激光加热方法（能够将样品加热到 300-4000 K），以研究极端 P-T 条件下的行星材料。广泛的 P-T 范围（1-3,000,000 atm 和 300-4000 K）使我们能够复制地球和行星内部的条件。此外，还使用定制的微型拉曼系统和同步加速器X射线光谱仪检查了相关材料的光谱特性。 在本提案中，我们合成了重要的深部地幔相（例如含氮硅酸盐和氮化铁、尖晶石、含锆硅酸盐和氧化物），并使用同步加速器X射线衍射、X射线光谱、拉曼和布里渊散射对它们进行了表征了解它们的结构和物理特性（例如密度、体积、弹性、强度、声速）。淬火至环境条件时的合成样品将通过电子探针微量分析和扫描电子显微镜进行检查，以了解样品内元素的分配和元素分布、氮化铁的熔化标准以及纳米级的晶体结构阶段。我们的目标是（1）评估地球和其他行星内部的氮预算，这对于未来的行星探索非常重要，（2）了解地球深处地震异常（例如超低速）的原因和机制，（ 3) 评估高 P-T 条件下的铬铁矿尖晶石多晶型物及其与冲击陨石的联系，以及 (4) 研究流行的行星冰（CO2、N2、CH4、NH3）的强度，这些冰可以被应用于行星内部动力学建模。 HQP 将接受高 P-T 矿物物理学方面的广泛培训，这将提供可转移的技能，为他们在学术、政府和私营部门就业做好准备。