EAGER: SUPER: Collaborative Research: Stabilization of Warm and Light Superconductors at Low Pressures by Chemical Doping

EAGER：SUPER：合作研究：通过化学掺杂在低压下稳定温光超导体

• 批准号: 2132574
• 负责人: Jianshi Zhou
• 金额: $ 20万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2132574&HistoricalAwards=false
• 关键词: EAGER; SUPER; Collaborative; Research; Stabilization

NONTECHNICAL SUMMARYThis award supports computational and experimental research and education aimed to result in the rational design and synthesis of materials that are superconducting at ambient temperatures and pressures. Superconductors can be used in many important technologies, including cables that transmit power without loss, electromagnets in magnetic resonance imaging machines and wind-turbines, extremely sensitive sensors, and as qubits in superconducting computers. Unfortunately, superconductivity in a material normally takes place at cryogenic temperatures, which is a major hurdle for applications. Recent major breakthroughs have shown that near room temperature superconductors can be made in materials that contain light elements, but only at pressures that surpass one million times atmospheric pressure. One class of known high pressure superconducting materials is based on cage-like structures made from hydrogen that are filled with metal atoms. The team will perform computations based upon quantum mechanics to pinpoint the best chemical species that can be added to these cage-like structures so that they retain their good superconducting properties even at lower pressures. Key to uncovering the most promising dopants will be the calculation of chemical pressure maps. Subsequently, diamond anvil cells and large volume presses will be employed to synthesize high-quality crystals of select compounds whose structures and properties will be experimentally determined. Analogous work will be performed on cage-like structures made from boron and carbon atoms.Graduate students will be exposed to a multi-disciplinary atmosphere, and learn how to communicate with experimentalists and theoreticians from different backgrounds. They will participate in outreach activities including mentoring undergraduates, especially from minority and underrepresented groups, and university open house events. The tight feedback loop between experiment and theory will provide a roadmap for future materials-by-design research.TECHNICAL SUMMARYThis award supports computational and experimental research and education aimed to result in the rational design and synthesis of materials that are superconducting at ambient temperatures and pressures. First-principles calculations of chemical pressure maps will be used to uncover the most promising chemical dopants for achieving high superconducting critical temperatures in light element systems stable at low, and even ambient pressures. The pressure-dependent stability, superconducting properties and spectroscopic signatures of these compounds will be calculated, and related to the chemical pressure maps. At the same time, novel pathways within laser heated diamond anvil cells and large volume presses will be used to synthesize high-quality crystals of the most promising candidates. Synchrotron single-crystal x-ray diffraction, Raman spectroscopy and transport properties will be measured, and compared with theoretical results to aid in structural, compositional, and physical property characterization. Electrical conductivity will be measured to verify superconductivity. This project will transform the way in which light element based high-temperature superconductors are designed, synthesized, and characterized.The PIs will focus on compounds related to the known binary superhydrides that contain clathrate cage-like structures because superconductivity has been measured in many of their members. The first class to be studied are boron/carbon analogues of the superhydrides because the replacement of the hydrogen atoms by light p-block elements that form strong covalent bonds will render some of these phases stable at normal pressures while retaining properties that are crucial for superconductivity. The second class are ternary superhydrides derived from the known binaries. Chemical pressure maps will reveal which elements have the correct radius to achieve a denser packing than in the binary hydride, while at the same time keeping the extended hydrogenic lattice required for the large electron phonon coupling. Experiments will map out the phase diagram by x-ray diffraction and Raman with laser heating under pressure.Students involved in this project will be trained in state-of-the-art theoretical and experimental techniques, and be exposed to a multi-disciplinary atmosphere where they learn to communicate with scientists from very different fields. The creation of materials that are superconducting at normal temperatures and pressures will have a tremendous impact on the electrical grid infrastructure, medical technology, renewable energy and lead to new innovations. The tight feedback loop between experiment and theory will advance the field of materials by design. The PIs will communicate with the popular science media about the breakthroughs made in this field, thereby educating the public and motivating future scientists.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.

该奖项支持计算和实验研究和教育，旨在合理设计和合成在环境温度和压力下超导的材料。超导体可用于许多重要技术，包括无损耗传输电力的电缆，磁共振成像机和风力涡轮机中的电磁铁，极其敏感的传感器以及超导计算机中的量子位。不幸的是，材料中的超导性通常发生在低温下，这是应用的主要障碍。最近的重大突破表明，近室温超导体可以在含有轻元素的材料中制成，但必须在超过一百万倍大气压的压力下才能实现。一类已知的高压超导材料是基于由氢制成的笼状结构，其填充有金属原子。该团队将根据量子力学进行计算，以确定可以添加到这些笼状结构中的最佳化学物质，以便即使在较低的压力下也能保持良好的超导性能。发现最有希望的掺杂剂的关键是计算化学压力图。随后，将采用金刚石压砧单元和大体积压机来合成选定化合物的高质量晶体，其结构和性能将通过实验确定。研究生们将在多学科的氛围中学习如何与来自不同背景的实验学家和理论家进行交流。他们将参加外联活动，包括辅导本科生，特别是来自少数民族和代表性不足群体的本科生，以及大学开放日活动。实验和理论之间的紧密反馈回路将为未来的材料设计研究提供路线图。技术总结该奖项支持计算和实验研究和教育，旨在合理设计和合成在环境温度和压力下超导的材料。化学压力图的第一性原理计算将用于揭示最有前途的化学掺杂剂，以实现在低压力甚至环境压力下稳定的轻元素系统中的高超导临界温度。这些化合物的压力依赖的稳定性，超导性质和光谱特征将被计算，并与化学压力图。与此同时，激光加热金刚石对顶砧单元和大体积压机内的新途径将用于合成最有前途的候选物的高质量晶体。同步加速器单晶X射线衍射，拉曼光谱和传输性能将被测量，并与理论结果进行比较，以帮助在结构，成分和物理性能表征。将测量电导率以验证超导性。该项目将改变基于轻元素的高温超导体的设计、合成和表征方式。PI将专注于与已知的含有笼形笼状结构的二元超导体相关的化合物，因为超导性已经在它们的许多成员中测量到。第一类要研究的是超导体的硼/碳类似物，因为氢原子被形成强共价键的轻p区元素取代，将使这些相在常压下稳定，同时保留对超导性至关重要的性质。第二类是从已知的二进制中派生出来的三进制超数。化学压力图将揭示哪些元素具有正确的半径，以实现比二元氢化物更致密的堆积，同时保持大电子声子耦合所需的扩展类氢晶格。实验将通过X射线衍射和拉曼与激光加热在压力下绘制相图。参与这个项目的学生将接受最先进的理论和实验技术的培训，并接触到一个多学科的氛围，在那里他们学习与来自不同领域的科学家进行交流。在正常温度和压力下超导材料的创造将对电网基础设施，医疗技术，可再生能源产生巨大影响，并导致新的创新。实验和理论之间的紧密反馈回路将通过设计推动材料领域的发展。该奖项反映了NSF的法定使命，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。