Simple Molecular Systems at Ultrahigh Pressures

超高压下的简单分子系统

• 批准号: 1933622
• 负责人: Russell Hemley
• 金额: $ 68.15万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1933622&HistoricalAwards=false
• 关键词: Simple; Molecular; Systems; Ultrahigh; Pressures

Nontechnical Abstract: The millions of atmospheres of pressure that can now be produced in the laboratory can impart profound effects on atoms and molecules, molding matter to make new materials with unprecedented properties. Conventional understanding fails to predict such effects, beginning with hydrogen, the first element in the Periodic Table, and extending to other "simple" elements. This project explores this new world of materials when compressed up to five million atmospheres (5 megabars or 500 gigapascals). A key property to be explored is superconductivity - the ability of a material to conduct electricity without resistance - at very high temperatures, including possibly room temperature and above. Advanced experimental techniques to study materials to very high pressures while at variable temperatures are employed to synthesize and characterize these materials, and theoretical and computational methods are used to interpret the results as well as to predict new materials and their properties to guide syntheses. The results have implications for fields beyond condensed-matter physics, including chemistry, advanced technology, planetary science, and astrophysics. An important goal is education and training of graduate students and undergraduates in the field. There is also a component that impacts locally STEM education and the public understanding of science.Technical Abstract: Pressure is not a simple thermodynamic parameter but an effective tool for the creation of exotic materials and phenomena not accessible at ambient conditions. Materials subjected to pressures up to several hundred gigapascals exhibit unexpected properties, including very high-temperature superconductivity, counterintuitive bonding patterns and electronic topological states, entirely new crystal structures, and potentially new physics. Investigations of materials at these conditions thus test both the limits of experimental techniques as well as fundamental theory. Addressing these questions in "simple" elemental and molecular systems at ultrahigh pressures, the project is divided into the following tasks: 1. Very High Tc Superconductivity; 2. Metallization and Novel Transitions in Dense Hydrogen; 3. High-Pressure Electrides; 4. Novel Interfacial Phenomena at Megabar Pressures; 5. Unconventional and Exotic Compounds; and 6. Methods and Technique Development. Each of the tasks involve tightly integrated experiment and computational theory. In particular, the experimental effort takes advantage of new developments in diamond-anvil techniques and capabilities at advanced radiation facilities to explore the nature of these materials in extreme conditions.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.

非技术摘要：现在在实验室中可以产生数百万个大气压的压力，可以对原子和分子产生深远的影响，塑造物质，使新材料具有前所未有的特性。传统的理解无法预测这样的效应，从氢开始，元素周期表中的第一个元素，并扩展到其他“简单”元素。这个项目探索了这个新的材料世界，当压缩到500万个大气压（5兆巴或500吉帕斯卡）时。有待探索的一个关键特性是超导性-材料在非常高的温度下（可能包括室温或更高温度）无电阻导电的能力。先进的实验技术，研究材料，以非常高的压力，而在可变的温度下合成和表征这些材料，理论和计算方法用于解释结果，以及预测新材料及其性能，以指导合成。这些结果对凝聚态物理学以外的领域具有影响，包括化学，先进技术，行星科学和天体物理学。一个重要的目标是教育和培训该领域的研究生和本科生。技术摘要：压力不是一个简单的热力学参数，而是一个有效的工具，可以用来创造在环境条件下无法获得的奇异材料和现象。承受高达几百吉帕斯卡压力的材料表现出意想不到的特性，包括非常高温的超导性，违反直觉的键合模式和电子拓扑状态，全新的晶体结构，以及潜在的新物理学。因此，在这些条件下对材料的研究既检验了实验技术的极限，也检验了基本理论的极限。为了解决这些问题，在“简单”的元素和分子系统在常压下，该项目分为以下任务：1。超高Tc超导性; 2.致密氢中的金属化和新跃迁; 3.高压电解质; 4.兆巴压力下的新型界面现象; 5.非常规和异国情调的化合物;和6。方法和技术开发。 每个任务都涉及紧密结合的实验和计算理论。 特别是，实验工作利用了金刚石砧技术的新发展和先进辐射设施的能力，以探索这些材料在极端条件下的性质。该奖项反映了NSF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。

项目成果

High-pressure study of the low- Z rich superconductor Be22Re

• DOI: 10.1103/physrevb.104.064505
• 发表时间: 2021-04
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: J. Lim;A. Hire;Y. Quan;J. Kim;L. Fanfarillo;S. Xie;R. Kumar;C. Park;R. Hemley;Y. Vohra-Y.-V

X-ray diffraction and equation of state of the C-S-H room-temperature superconductor.

• DOI: 10.1063/5.0064750
• 发表时间: 2021-05
• 期刊: The Journal of chemical physics
• 作者: Anmol Lamichhane;Ravhi S Kumar;M. Ahart;N. Salke;N. Dasenbrock-Gammon;Elliot Snider;Y. Meng