Collaborative: EAGER: Demonstration that Thin Film Phase Transformations Can Be Monitored at High-Temperature and High-Pressure in a Diamond Anvil Cell

协作：EAGER：证明可以在金刚石砧池中的高温高压下监测薄膜相变

• 批准号: 2031331
• 负责人: Jason Nicholas
• 金额: $ 6.5万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-15 至 2023-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2031331&HistoricalAwards=false
• 关键词: Collaborative; EAGER; Demonstration; Thin; Film

Phase transitions and the associated volume changes strongly influence materials’ properties. When occurring in minerals in subduction zones - where one tectonic plate dives underneath another - they may cause earthquakes. Preliminary observations suggest that phase boundaries (where transitions occurred) are influenced by changes in mineral grain size and stress state. However, such effects are still poorly understood because of experimental limitations. Indeed, it is challenging to tune minerals’ grain size and stress state at the extreme pressures and temperatures prevailing in subduction zones. Here, the researchers explore the capabilities of a new experimental approach which allows such tuning. They produce thin films of mineral with controlled grain size and stress state using state-of-the-art deposition techniques. They then probe the mineral stability at the extreme conditions of the deep Earth using high-pressure devices. This work fosters technological transfers between Materials Science and Mineral Physics. Its outcomes have broad implications, notably regarding the stability of thin films for incorporation into everyday devices. The project also provides support for a graduate student trained in a multidisciplinary environment.Here, silica (SiO2) thin films with variable crystallite sizes and biaxial stress states are fabricated via Pulsed Laser Deposition by modulating the growth conditions and choice of substrate. These thin films are then placed within the independently modulated hydrostatic stress field of a diamond anvil cell. This high-pressure device can produce very high pressures at the tips of two opposing diamonds. The films’ properties are probed in situ with visible light and/or x-rays at various pressures and temperatures. The goal is to map out how given SiO2 crystallite size and/or biaxial stress state changes the pressure and temperature conditions of silica phase boundaries. More generally, the team explores whether Pulsed Laser Deposition can produce geologically relevant thin films with tunable stress states, crystallite sizes and orientations. Such a novel tool could be transformative for the study of phase transformations - as well as other processes related to transport properties and chemical reactions - occurring in the deep Earth.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

相变和相关量的变化强烈影响材料的特性。当发生在俯冲带中的矿物质中时 - 一个构造板在另一个构造板上潜水 - 它们可能会引起地震。初步观察结果表明，相位边界（发生过渡的地方）受矿物晶粒尺寸和应力状态的变化影响。但是，由于实验性局限性，这种影响仍然很少理解。的确，在俯冲带中普遍存在的极端压力和温度下，调整矿物质的晶粒尺寸和应力状态是具有挑战性的。在这里，研究人员探索了一种新的实验方法的功能，该方法允许进行调整。它们使用最先进的沉积技术生产具有控制晶粒尺寸和应力状态的矿物质薄膜。然后，他们使用高压装置在深层地球的极端条件下探测矿物稳定性。这项工作促进了材料科学与矿物质物理学之间的技术转移。它的结果具有广泛的含义，特别是关于薄膜对公司每天设备的稳定性。该项目还为在多学科环境中接受训练的研究生提供了支持。在这里，二氧化硅（SIO2）薄膜具有可变的晶体大小，双轴应力状态是通过调节生长条件和底物的选择来通过脉冲激光沉积制造的。然后，将这些薄膜放置在钻石砧细胞的独立调制静水应力场中。这种高压装置可以在两根相对的钻石的尖端产生很高的压力。膜的特性在原位探测，可见光和/或X射线在各种压力和温度下进行探测。目的是绘制给定给定的SIO2晶体大小和/或双轴应力状态如何改变二氧化硅相边界的压力和温度条件。更普遍地，该团队探讨了脉冲激光沉积是否可以产生具有可调式应力状态，结晶石大小和方向的地质相关薄膜。这种新颖的工具对于研究相变的研究以及与运输特性和化学反应有关的其他过程可能具有变革性。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛影响的审查标准通过评估来获得支持的。