Convergent Materials Design: Pressure Tuning Superconductivity via Polymorphism Control

Johns Hopkins University, Baltimore MD

Investigators

Abstract

PART 1: NON-TECHNICAL SUMMARY The 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 SUMMARY The 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.