Atom Probe Tomography (APT) development and optimization for applications in Earth Sciences

地质学家试图通过研究岩石来回答有关地球如何运转的问题。例如，岩石能告诉我们地球的年龄吗？关于陨石的起源以及它们在行星形成中的作用，我们能知道些什么呢？岩石甚至可以让我们研究火山爆发和地震等地球过程。地质学家利用岩石来更好地了解地球及其过程的一种方法是观察特定的化学元素，如铀、碳、氧和氮，这些元素存在于形成岩石的矿物中。直到最近，地质学家还无法研究这些矿物的化学成分，这限制了他们了解矿物如何形成和复制这种形成，或记录和解释地质过程的能力。该奖项将资助一项技术的发展，该技术将使地质学家能够看到矿物内部并分析元素（即原子）的最基本组成部分。在阿拉巴马大学，我们有最新的仪器可以分析岩石中的原子。我们还将利用这笔资金培训学生使用这种仪器，并邀请美国各地的地质学家合作使用我们的设备。这项技术使地质学家能够从一个新的角度来观察矿物中的化学成分，最终可以更好地理解火山是如何工作的，宝石是如何形成的，石油和天然气是如何被困在岩石中的，以及其他对我们社会重要的地质过程。有了这些新知识，地质学家将能够预测和减轻灾害，复制目前有限的资源，并以对环境无害的方式生产和利用能源。一个多世纪以来，化学矿物学研究一直是地球科学信息的主要来源，因为矿物在其形成期间和之后积极地记录了地质过程。原子探针层析成像（APT）最近被添加到目前可用的矿物表征技术中。这项技术可以在原子尺度上提供矿物化学的基本信息，并为纳米尺度材料的三维信息分析提供了额外的可能性。尽管地球科学对APT的兴趣日益浓厚，但这种新型分析技术的使用仍然非常有限。该提案的资金将用于开发和优化原子探针层析成像技术，用于地质研究中重要矿物的高分辨率地球化学表征。这项工作有望帮助地质学家在以下方面更好地将矿物学和地球化学联系起来：1)矿物中的扩散动力学（体积、晶界、微量元素等）；ii)元素划分；iii)同位素分馏；iv)矿物溶解和再结晶；v)瞬态非晶相转变为晶相。资金还将用于培训纳米地球化学领域的新一代地球科学家，并通过直接的研究伙伴关系和机构合作，向美国各地的地质学家提供我们在阿拉巴马大学的APT设施。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Geologists try to answer questions about how the Earth works by studying rocks. What, for example, can rocks tell us about the age of the Earth? What can we know about the origin of those rocks we call meteorites and their role in planet formations? Rocks even allow us to examine Earth processes like volcanic eruptions and earthquakes. One way geologists use rocks to better understand the Earth and its processes is by looking at specific chemical elements, such as uranium, carbon, oxygen and nitrogen, that are found in the minerals that form rocks. Until recently, geologists have been unable to examine the chemistry of those minerals beyond their elements, which has limited their ability to understand how minerals form and replicate that formation or record and explain geological processes. This award will fund the development of a technique that will allow geologists to see inside minerals and analyze the most basic components of elements, that is to say atoms. At the University of Alabama, we have the newest instrument that can analyze atoms in rocks. We will also use the funding to train students to use this instrument and to invite geologists across the United States to collaborate and use our facilities. This technique allows geologists to see the chemistry in minerals from a new perspective that can ultimately produce a better understanding of how volcanoes work, how gems form, how oil and gas are trapped in rocks, among other geological processes with importance to our society. With this new knowledge, geologists will be able to, for example, predict and mitigate hazards, replicate resources that are currently limited, and produce and harness energy in ways that are harmless to the environment.The study of chemical mineralogy has been a major source of information within Earth Sciences for more than a century, as minerals actively record geological processes during and after their formation. Atom probe tomography (APT) has been recently added to the currently available techniques for the characterization of minerals. This technique can provide fundamental information about mineral chemistry at atomic scale and offers the additional possibility of analyzing information in 3D for nanoscale volumes of material. Despite a rising interest on APT in Geosciences, the use of this novel analytical technique is still very limited. Funding for this proposal will be used to develop and optimize the technique of atom probe tomography for high-resolution geochemical characterization of minerals of importance in geological studies. This work is expected to help geologists better link mineralogy and geochemistry with regards to the following aspects: i) Diffusion kinetics in minerals (volume, grain-boundary, trace elements, etc.); ii) Element partitioning; iii) Isotopic fractionation; iv) Mineral dissolution and recrystallization; and v) Transformation of transient amorphous phases into crystalline counterparts. Funding will be also used to train a new generation of geoscientists in nanogeochemistry and to provide access to geologists across the United States to our APT facilities at the University of Alabama through direct research partnerships and institutional collaborations.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.