EAGER: In Situ Determination of Synthetic Intermediates - Investigating the Path to Lead Apatite Room Temperature Superconductors

EAGER：合成中间体的原位测定 - 研究铅磷灰石室温超导体的路径

• 批准号: 2403727
• 负责人: Allyson Fry-Petit
• 金额: $ 30万
• 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: 2023
• 资助国家: 美国
• 起止时间: 2023-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2403727&HistoricalAwards=false
• 关键词: EAGER; Situ; Determination; Synthetic; Intermediates

PART 1: NON-TECHNICAL SUMMARYSuperconductivity, or the total lack of resistance to electrical conductivity, is a property of materials that has broad applications, from life-saving imaging to more efficient computing. Currently, it can only be utilized under extreme conditions. Thus, when a superconductor that operates at reasonable conditions was reported in the summer of 2023, the scientific community was excited to explore it. The superconductor contained copper, lead and oxygen, and original reports showed it would levitate over a magnet above room temperature, a property that allows superconductors to be used in high-speed trains. However, subsequent reports found that when other researchers attempted to study the material, they did not observe superconductivity. This is potentially because the original sample was a complex mixture. This EAGER award, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, aims to reproduce the synthesis of the original material and expand to related structures and monitor what compounds form during the synthesis utilizing a method called in situ diffraction. Such an approach can determine all phases that exist when attempting to prepare any kind of superconducting material even if they are not stable and part of the final product, hence providing valuable insights. Because it is uncertain if the project yields new or confirms a previously proposed superconducting materials, it is a high-risk/high-reward endeavor. With this project the principal investigator at CSU Fullerton, which is a Primarily Undergraduate Institution, introduces undergraduate students not only to cutting-edge research but also provides them with opportunities to travel to user facilities at National Laboratories. PART 2: TECHNICAL SUMMARY A report in the summer of 2023 of an above-room-temperature superconductor, LK-99, stirred excitement in the chemistry and physics communities. However, attempts to reproduce the initially observed superconductivity were unsuccessful. The main goal of this proposal is to understand the synthetic mechanisms resulting in the reported high-temperature superconductor LK-99 and establish general structure-property relationships for lead apatite materials and related compounds. For this purpose, this EAGER award, which is supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, relies heavily on in situ and ex situ diffraction and total scattering methods, and thereby, can determine all phases present in the synthesis of LK-99 and copper-doped lead apatite. Moreover, in situ methods rapidly elucidate the conditions under which these phases form. For more in depth characterization, high-resolution ex situ diffraction and total scattering are utilized on phases quenched at specific conditions of interest as determined by in situ methods to identify potentially superconducting or ferromagnetic phases. Performing these experiments allows the principal investigator and her research group to identify possible intermediate phases that show superconducting or ferromagnetic properties not limited to the ones identified in the original report.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.

第一部分：非技术概述超导性，或完全没有电阻的导电性，是一种具有广泛应用的材料特性，从拯救生命的成像到更有效的计算。目前，它只能在极端条件下使用。因此，当2023年夏天报道了一种在合理条件下运行的超导体时，科学界兴奋地对其进行了探索。这种超导体含有铜、铅和氧，最初的报告显示，它可以在室温以上的磁体上悬浮，这一特性使超导体能够用于高速列车。然而，随后的报告发现，当其他研究人员试图研究这种材料时，他们没有观察到超导性。这可能是因为原始样品是复杂的混合物。EAGER奖由NSF材料研究部的固态和材料化学计划支持，旨在重现原始材料的合成，并扩展到相关结构，并利用称为原位衍射的方法监测合成过程中形成的化合物。这种方法可以确定在试图制备任何类型的超导材料时存在的所有相，即使它们不稳定并且是最终产品的一部分，因此提供了有价值的见解。由于不确定该项目是否产生新的或证实先前提出的超导材料，因此这是一项高风险/高回报的奋进。通过这个项目，CSU Fullerton的首席研究员不仅向本科生介绍了前沿研究，还为他们提供了前往国家实验室用户设施的机会。第二部分： 2023年夏天，一份关于高于室温的超导体LK-99的报告在化学和物理界引起了轰动。然而，试图重现最初观察到的超导性是不成功的。该提案的主要目标是了解导致高温超导体LK-99的合成机制，并建立铅磷灰石材料和相关化合物的一般结构-性质关系。为此，EAGER奖由NSF材料研究部门的固态和材料化学计划支持，主要依靠原位和非原位衍射和总散射方法，从而可以确定LK-99和铜掺杂铅磷灰石合成中存在的所有相。此外，原位方法可快速阐明这些相形成的条件。对于更深入的表征，高分辨率的非原位衍射和总散射被用于在特定条件下淬火的相，如通过原位方法确定的，以识别潜在的超导或铁磁相。通过这些实验，首席研究员和她的研究小组可以识别出可能的中间相，这些中间相显示出超导或铁磁特性，而不限于原始报告中确定的那些。该奖项反映了NSF的法定使命，并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，被认为值得支持。