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; 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：现在可以在实验室中产生的数百万个压力大气可以对原子和分子产生深远的影响，使其成型物质以制造具有前所未有的特性的新材料。传统的理解无法预测这种影响，从氢，这是周期表中的第一个元素，并扩展到其他“简单”元素。当压缩多达500万个气氛（5兆巴或500吉帕斯卡）时，该项目探讨了这种新的材料世界。要探索的关键特性是超导性 - 在非常高的温度下（包括室温及以上），材料无电力传导电力的能力。高级实验技术用于研究材料至非常高的压力，而在可变温度下则用于合成和表征这些材料，并且使用理论和计算方法来解释结果，并预测新材料及其特性来指导合成。结果对除凝结物理学的领域具有影响，包括化学，先进技术，行星科学和天体物理学。一个重要的目标是对该领域的研究生和本科生的教育和培训。还有一个影响当地教育和对科学的公众理解的组成部分。技术摘要：压力不是一个简单的热力学参数，而是在环境条件下无法获得异国情调材料和现象的有效工具。受到高达数百gigapascal的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，反直觉粘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实验技术的局限性，又要检验基本理论。在超高压力下，在“简单”元素和分子系统中解决这些问题，该项目分为以下任务：1。TC非常高的超导性； 2。金属化和致密氢的新型过渡； 3。高压电气； 4。巨大压力的新型界面现象； 5。非常规和外来化合物；和6。方法和技术开发。 每个任务都涉及紧密整合的实验和计算理论。 特别是，实验努力利用了高级辐射设施中钻石 - 大安维尔技术和能力的新发展，以在极端情况下探索这些材料的性质。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知识分子优点和更广泛的影响审查标准来通过评估来通过评估来支持的。