Probing Molecular Quantum Materials by Advanced Spectroscopies

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

With support from the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, Professor Ziling Xue of the Department of Chemistry at the University of Tennessee-Knoxville is developing new classes of molecular quantum materials based on metal complexes and advanced techniques to characterize the materials. One goal of this research is to exploit the characteristics of new Haldane topological materials for the development of spintronic devices and future quantum computers. The other goal is to understand the properties of single-molecule magnets (SMMs) for potential applications in ultra-high density data storage, quantum computation, and cryogenic magnetic refrigeration. The project is interdisciplinary involving inorganic, organic, physical, and materials chemistry. It offers students opportunities to use state-of-the-art facilities at national laboratories in research, broadening their educational background and training. Outreach activities in the project involve high school students to help attract potential first-generation college students from low-income families to the sciences. Spin-1 Haldane chains with oxalate ligands in metal-organic frameworks (MOFs) are a unique type of topological materials, offering neutral, 2D structures with a rich array of magnetic and photophysical properties. In this project, new Haldane materials in MOFs, including those with high-spin Mn(III) spin-2 chains and ligands other than oxalate, will be investigated to understand the unique Haldane-type couplings between neighboring metal ions. For single-molecule magnets (SMMs), spin-phonon and spin-spin couplings, leading to magnetic relaxation, are key to the performance of SMMs. The SMM research in this project includes the following aims: (1) to study intermolecular magnetic interactions between molecules in solids by the unique Q dependence of magnetic peaks in inelastic neutron scattering (INS, Q = length of neutron scattering vector Q); (2) to probe spin-phonon coupling in an SMM by 4D INS and (3) to expand studies of spin-phonon couplings, especially the role of symmetry in Raman spectroscopy. 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.