High-Pressure Synthesis of Missing Pnictide Superconductors

缺失磷族超导体的高压合成

• 批准号: 2220706
• 负责人: Danna Freedman
• 金额: $ 42.88万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2220706&HistoricalAwards=false
• 关键词: Pressure; Synthesis; Missing; Pnictide; Superconductors

Part 1: Non-Technical summary: Lossless transmission of power means that all electricity that goes into a material is transported without loss. If achieved, this would lead to astonishing energy savings, completely transform energy generation, and significantly improve medical imaging technology. So-called superconductors demonstrate this lossless transmission of electricity making them very important for novel technologies. Superconductors also offer the potential for fundamental scientific discovery. The mechanism by which superconductors enable this energy saving phenomenon is largely not well understood. Understanding this mechanism and creating better superconductors is essential for technological application, because currently superconductivity is largely a low-temperature phenomenon, with critical temperatures for superconductors being similar to the extremely low temperatures found on Mars or even in the coldest regions of outer space. Through this award, funded by the Solid State and Materials Chemistry as well as the Condensed Matter Physics programs in the Division of Materials Research at NSF, Freedman's research team engages in a theory-inspired search for new superconductors of a specific type, which could enable fundamental insight into the mechanism of superconductivity. Her team uses high-pressure synthesis to access new compounds that have long eluded chemists. This work enables interdisciplinary training for graduate students and postdoctoral fellows, where they benefit from the scientific intersection of solid-state chemistry, physics and geophysics. Preparing graduate students to collaborate across fields strengthens the next generation of our scientifically engaged workforce.Part 2: Technical summary: The realization of high temperature superconductivity would be a transformative advance, with implications across NSF directorates ranging from improved medical imaging to fault tolerant power transmission. Thus far, the vast majority of new superconductors have been found either by serendipity, modification of known superconducting systems, or through the investigation of theoretically unlikely candidates. In stark contrast, the targeted synthesis of new systems is underdeveloped, owing to the inherent difficulty of predicting new superconducting materials. To enable rational progress, a clear design strategy is needed, which necessitates knowing the operative superconducting mechanism in a given class of superconductors. Freedman proposes the synthesis of the notably missing subclass of Fe-Bi pnictide superconductors via high-pressure synthesis. This work is motivated by Freedman's recent discovery of the first Fe-Bi bond in the solid-state, achieved through the application of high pressure and stabilized by the formation of Bi-Bi interactions. Through this award, funded by the Solid State and Materials Chemistry as well as the Condensed Matter Physics programs in the Division of Materials Research at NSF, Freedman's team characterizes novel materials both through in situ and bulk X-ray diffraction and spectroscopic methods. Materials are physically probed via magnetometry, resistivity, and heat capacity measurements. The aggregate of these data provides insight into the mechanism of superconductivity, and possible structure-function correlations. Creating and understanding different superconductors offers promise for true discovery within this complex field. The realization of a new class of superconductors would foster collaborations across the sciences and enable a deeper understanding of superconductivity. Superconductors also have tremendous potential for societal impact, ranging from MRI instrumentation to increased power transmission through the electric grid.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.

第1部分：非技术总结：电力的无损传输意味着进入材料的所有电力都没有损失。如果实现，这将带来惊人的节能，彻底改变能源生产，并显着提高医学成像技术。所谓的超导体展示了这种电力的无损传输，这使得它们对新技术非常重要。超导体也为基础科学发现提供了潜力。超导体实现这种节能现象的机制在很大程度上还没有得到很好的理解。理解这种机制并创造更好的超导体对于技术应用至关重要，因为目前超导性在很大程度上是一种低温现象，超导体的临界温度与火星上甚至外太空最寒冷地区的极低温度相似。通过这个奖项，由固体和材料化学以及在NSF材料研究部门的凝聚态物理计划资助，弗里德曼的研究团队从事理论启发的搜索特定类型的新超导体，这可以使基本洞察超导机制。她的团队使用高压合成来获得化学家们长期以来无法获得的新化合物。这项工作为研究生和博士后研究员提供了跨学科培训，使他们受益于固态化学，物理学和电子物理学的科学交叉。第二部分：技术总结：高温超导的实现将是一个变革性的进步，其影响范围从改进医学成像到容错电力传输，涉及到NSF的各个部门。到目前为止，绝大多数新的超导体都是通过偶然发现，对已知超导系统的修改，或者通过对理论上不太可能的候选者的研究而发现的。与此形成鲜明对比的是，由于预测新超导材料的固有困难，新系统的目标合成还不发达。为了实现合理的进展，需要一个明确的设计策略，这就需要知道给定类别超导体的超导机制。弗里德曼提出了通过高压合成法来合成Fe-Bi磷属元素化物超导体的明显缺失的子类。这项工作的动机是弗里德曼最近发现的第一个Fe-Bi键在固态，通过应用高压和稳定的Bi-Bi相互作用的形成。通过该奖项，弗里德曼的团队通过原位和体相X射线衍射和光谱方法表征了新材料，该奖项由美国国家科学基金会材料研究部的固态和材料化学以及凝聚态物理项目资助。通过磁力测量、电阻率和热容测量对材料进行物理探测。这些数据的集合提供了对超导机制的深入了解，以及可能的结构-功能相关性。创造和理解不同的超导体为在这个复杂的领域中进行真正的发现提供了希望。实现一种新的超导体将促进跨科学的合作，并使人们能够更深入地了解超导性。超导体还具有巨大的社会影响潜力，从MRI仪器到通过电网增加电力传输。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。