Convergent Materials Design: Pressure Tuning Superconductivity via Polymorphism Control

合理地发现新的超导体，即无电阻导电的材料，仍然是化学和物理领域尚未解决的材料挑战。简单地说，甚至如何处理这个问题都是未知的。然而，实现这一目标有可能通过更便宜、更高效的电力分配、改进的手机信号塔和增强的医疗成像来造福社会。这项工作由材料研究部固态和材料化学项目支持，重点是通过迭代设计材料来确定超导体的适当设计原则。材料合成、压力相关结构和物理特性表征以及计算建模的结合将用于建立结构-性能关系。了解这些关系将反过来产生设计原则，使科学家能够拼凑出新的超导体，从而为社会带来下一代技术效益。当地社区的参与，包括来自摩根州立大学的电气工程专业的学生，将通过提供材料和电气工程领域之间知识的交叉施肥，进一步扩大影响，并且固态电子材料的新课堂和实践模块的实施将有助于培养下一代劳动力。PIs提出在层状电子材料中建立新的结构功能关系和新材料发现的设计原则，特别是针对超导状态。为此，将结合材料合成、压力下的物理性质和结构表征测量、化学键模型和密度泛函理论（DFT）进行应用。需要解决的具体问题包括：1)对称、多态和超导之间的联系是什么？2)维度如何影响超导性？利用电子结构计算，pi已经确定了一类鲜为人知的材料，这些材料将为这些问题提供前所未有的见解：前者通过瞄准结构参数的伴随变化，而后者通过提供具有柔性化学基序的双层铁肽的第一个例子。这些设计原则是通过压力相关的测量和计算来阐明的，将迭代地应用于环境压力下改进材料的进一步设计原则。此外，迭代设计材料在超导中的应用将证明，一个不存在明确预测理论的问题，如何仍然可以通过现代设计材料方法得到显著改善。当地社区的参与，包括来自摩根州立大学的电气工程专业的学生，将通过提供材料和电气工程领域之间的知识交流，进一步扩大影响。固态电子材料的新课堂和实践模块的实施将有助于培养下一代劳动力，内容免费公开供他人使用。本项目由材料研究部固态与材料化学项目资助。该奖项反映了美国国家科学基金会的法定使命，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。

PART 1: NON-TECHNICAL SUMMARYThe rational discovery of new superconductors, materials that conduct electricity without resistance, remains an unsolved materials challenge in chemistry and physics. Simply stated, even how to approach this problem is unknown. Yet achieving this goal has the potential to benefit society with cheaper and more efficient electrical distribution, improved cell towers, and enhanced medical imaging. The proposed work, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, is centered on identifying appropriate design principles for superconductors through iterative materials-by-design. A combination of materials synthesis, pressure-dependent structural and physical property characterization, and computational modeling will be used to establish structure-property relationships. Understanding these relationships will in turn yield design principles allowing scientists to piece together new superconductors, enabling the next generation of technological benefits to society. Involvement of the local community, including electrical engineering students from Morgan State University, will further extend the impact by providing cross-fertilization of knowledge between the materials and electrical engineering fields, and the implementation of new classroom and hands-on modules on solid-state electronic materials will help train the next-generation workforce. PART 2: TECHNICAL SUMMARYThe PIs propose to establish novel structure-function relationships and design principles for new materials discovery in layered electronic materials, specifically aimed toward the superconducting state. To do so, a combination of materials synthesis, physical property and structural characterization measurements under pressure, chemical bonding models, and density functional theory (DFT) will be applied. Specific questions to be addressed include: 1) what is the connection between symmetry, polymorphism, and superconductivity?; and 2) how does dimensionality impact superconductivity? Using electronic structure calculations, the PIs have identified a class of lesser-known materials that will provide unprecedented insight into each of these questions: in the former by targeting concomitant changes in structural parameters, and in the latter by providing the first example of bilayer iron pnictides with flexible chemical motifs. These design principles, which are elucidated through pressure-dependent measurements and computation, will be applied iteratively to inform further design principles for improved materials at ambient pressure. In addition, the application of iterative materials-by-design to superconductivity will demonstrate how a problem for which definitive predictive theories do not exist can still be significantly enhanced by modern materials-by-design approaches. Involvement of the local community, including electrical engineering students from Morgan State University, will further extend the impact by providing cross-fertilization of knowledge between the materials and electrical engineering domains. The implementation of new classroom and hands-on modules on solid-state electronic materials will help train the next generation workforce, with the content freely and publicly available for use by others. This project is supported by the Solid State and Materials Chemistry program in the Division of Materials Research.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.