Defining Reaction Paths for Chalcogenide Materials Discovery

Northwestern University, Evanston IL

Investigators

Abstract

PART 1: NON-TECHNICAL SUMMARY The use of new materials is essential for societal advancement, and solid state materials are critical to the modern economy. With this project, supported by the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research, the principal investigator and his research group develop fundamental principles of synthesis and apply them to the chemistry of metal chalcogenides, which are important in various scientific investigations and technologies. Thereby they pursue challenging new directions, discover and synthesize new materials. The project focuses on controlling reactions leading to solid state chalcogenides to avoid known materials and studying their crystal structure, physical properties, and potential technological impact. This research challenges and enhances scientific understanding in this field of chemistry and improves existing technological applications while impacting new ones. For example, the reseach leads to the discovery of new atomic arrangements and novel semiconductors, quantum materials, and ion-exchange sorbent materials for environmental remediation. The project also significantly impacts the training, problem-solving abilities, and pedagogy of graduate students specializing in solid-state and materials synthesis. It aids in developing a competent workforce that comprehends the role of novel materials as catalysts for cutting-edge science and technology. Moreover, the project presents a range of opportunities for graduate and undergraduate students, particularly those from underrepresented communities, to acquire critical thinking skills that will advance scientific research in the future. PART 2: TECHNICAL SUMMARY The project, supported by the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research, addresses the development of tools, concepts, and reaction paths, both intellectual and experimental, to prepare new materials rationally. It is centered around fundamental science questions: (a) Can new semiconductors be designed by finding proper reaction paths? (b) Can insights from flux and non-flux reaction studies aid targeted synthesis? (c) Can distinct reaction paths be categorized for generalized synthetic methodologies? (d) Can chalcogenides' diverse motifs lead to enhanced properties? The research pursues new directions that have proven very challenging to date. For example, the pursuit of new phases by a) stuffing aristotype structures (in other words, to create new materials by inserting extra atoms in compounds possessing some of the most common structure types. Aristotype is a high-symmetry crystallographic structure type that can be viewed as an idealized version of a lower-symmetry structure), b) stabilizing novel tellurometallate building blocks in extended structures, c) developing synthesis of mixed anion compounds oxy-chalcogenides in a rational manner using a new kind of flux. These aspects represent the cutting edge of chalcogenide solid-state chemistry. They align with the principal investigator’s ongoing interest in novel physical properties of new compounds beyond mere structural characterizations. The benefits of a successful project are broad insights advancing the cutting edge of solid state and materials chemistry, the discovery of novel materials with attractive physical and chemical properties and potential applications, and new knowledge of reaction paths leading to new chalcogenides. 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.