LEAPS-MPS: Interrogating Negative Thermal Expansion in Earth-Abundant Oxide Materials

LEAPS-MPS：探究地球上丰富的氧化物材料中的负热膨胀

• 批准号: 2137437
• 负责人: Joya Cooley
• 金额: $ 23.92万
• 依托单位: CSU Fullerton Auxiliary Services Corporation
• 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: 2021-09-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2137437&HistoricalAwards=false
• 关键词: LEAPS; MPS; Interrogating; Negative; Thermal

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Non-Technical SummaryThermal expansion, the way materials change shape when you heat or cool them, is an important property to be able to understand and control. Many objects that people rely on every day (i.e. building materials, aerospace parts, etc.) can wear out or fail more easily if their thermal expansion is not matched well, thus creating more waste and higher costs in the world. While many materials expand as you heat them, some materials shrink as you heat them and are important to study. Therefore, it is important to understand how to control these properties so that new types of materials can be engineered. With this LEAPS-MPS project, Professor Joya Cooley at California State University, Fullerton, will focus on understanding why certain classes of materials which consist of earth-abundant elements shrink instead of expanding upon heating. The research is conducted at a primarily undergraduate institution where undergraduate students will be trained in a variety of synthetic and characterization techniques. Specifically, students from historically underserved backgrounds will be recruited to work on this project and will disseminate findings to the public through local outreach, allowing participating students to serve as role models for future scientists from historically underserved backgrounds. Furthermore, this local outreach will work to increase the amount of citizen science, public scientific literacy, and overall public interest in materials chemistry.Technical SummaryThis LEAPS-MPS award is aimed at understanding structural and chemical driving forces that lead to technologically relevant negative thermal expansion (NTE) in materials. This work will interrogate local and long-range structure in materials crystallizing as metal pyrophosphates and pyrovanadates (A2B2O7) using inexpensive and readily accessible elements (e.g., A = Mg, Mn, Co, Ni, Cu; B = P, V). The goal is to achieve the following: (1) investigate the role of A and B site elements and their influence on parent crystal structure; (2) understand the role of A and B site elements and their role in tuning temperature and range of NTE. The ability to vary metal (A) and nonmetal (B) identities in pyrophosphate (A2P2O7) and pyrovanadate (A2V2O7) materials by creating solid solutions provides a wealth of exploration possibilities for uncovering the structural drivers for NTE. By creating solid solutions between end members with properties at the extremes, this work will seek to elucidate the structural and chemical variables important to O motion that results in systematic control of NTE. This project will make use of (a) high resolution structural techniques, such as synchrotron diffraction; (a) techniques sensitive to light elements like O, such as neutron diffraction; (c) and techniques that provide a local understanding of atom motion, such as temperature dependent microscopy. Undergraduate students will be trained in solid-state chemistry techniques, including the opportunities to work with national laboratories for remote or hands-on experiments. Historically underserved students will be recruited to be part of this project and will engage in local outreach to increase public scientific interest and literacy.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.

该奖项全部或部分由2021年美国救援计划法案（公法117 - 2）资助。非技术摘要热膨胀，即材料在加热或冷却时改变形状的方式，是一个重要的属性，能够理解和控制。人们每天依赖的许多物体（即建筑材料，航空航天部件等）如果它们的热膨胀不能很好地匹配，则会更容易磨损或失效，从而在世界上产生更多的浪费和更高的成本。虽然许多材料在加热时会膨胀，但有些材料在加热时会收缩，这对研究很重要。因此，重要的是要了解如何控制这些属性，以便可以设计新类型的材料。在这个LEAPS-MPS项目中，加州州立大学富勒顿分校的Joya Cooley教授将专注于理解为什么由地球丰富的元素组成的某些类别的材料会在加热时收缩而不是膨胀。 这项研究是在一个主要的本科院校进行的，本科生将接受各种合成和表征技术的培训。具体而言，将招募来自历史上服务不足背景的学生参与该项目，并将通过当地宣传向公众传播研究结果，让参与的学生成为来自历史上服务不足背景的未来科学家的榜样。此外，这一地方推广活动将致力于增加公民科学的数量，公众科学素养，以及公众对材料化学的整体兴趣。技术摘要该LEAPS-MPS奖项旨在了解导致材料中技术相关负热膨胀（NTE）的结构和化学驱动力。这项工作将询问局部和远程结构的材料结晶为金属焦磷酸盐和焦钒酸盐（A2B2O7）使用廉价和容易获得的元素（例如，A = Mg、Mn、Co、Ni、Cu; B = P、V）。目的是：（1）研究A和B位元素的作用及其对母体晶体结构的影响;（2）了解A和B位元素的作用及其在调节NTE温度和范围中的作用。通过形成固溶体来改变焦磷酸盐（A2P2O7）和焦钒酸盐（A2V2O7）材料中的金属（A）和非金属（B）身份的能力为揭示NTE的结构驱动因素提供了丰富的探索可能性。通过创建端元之间的固溶体与极端的属性，这项工作将寻求阐明的结构和化学变量的重要O运动，导致系统控制的NTE。该项目将利用（a）高分辨率结构技术，如同步加速器衍射;（a）对O等轻元素敏感的技术，如中子衍射;（c）提供对原子运动的局部了解的技术，如随温度变化的显微镜。本科生将接受固态化学技术的培训，包括与国家实验室合作进行远程或动手实验的机会。历史上服务不足的学生将被招募成为这个项目的一部分，并将参与当地的推广活动，以提高公众的科学兴趣和素养。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。