RII-Track 4: Investigation into Structure-Magnetism Correlations in 4d/5d Transition Metal Halides using Combined X-ray and Neutron Diffraction Techniques

量子材料是未来能源和信息技术革命的关键，量子力学的非凡效应可以诱导独特和意想不到的行为。该提案旨在在路易斯安那州立大学（LSU）建立一个强大的无机材料研究项目，目标是解决具有挑战性的问题，以发现具有奇异物理性质的新量子材料。通过对晶体结构、物理性质和化学键之间关系的基本理解，我们将合成和表征新型量子材料，目的是了解磁性与它们的化学成分和原子结构之间的关系。该奖学金将为PI在橡树岭国家实验室（ORNL）学习中子衍射技术提供一个独特的机会。这将为路易斯安那州立大学的材料研究提供一个新的方向，重点是从化学的角度寻找新的量子材料，并促进量子材料在物理和化学中的跨学科研究。迄今为止，自旋轨道耦合（SOC）在4d/5d基化合物中产生电子基态的重要性已经出现，并且揭示了许多通往各种非常规物理状态的新途径。例如，像量子材料，像量子自旋液体、Weyl半金属和轴子绝缘体，它们具有很强的自旋轨道耦合，可能在数据存储和内存、电子和量子计算中有应用。该项目旨在设计、合成和表征基于分子的无机4d/5d过渡金属卤化物，目的是了解磁性与其化学成分和原子结构的关系，并随着时间的推移促进技术应用。目前，主要的实验和理论工作都是在S=1/2的各种d5系统中寻找新的自旋轨道耦合系统。我们将研究结构-磁性相互作用，并了解电子-电子相关(U)、自旋-轨道耦合（SOC）和晶体场理论（CFT）的复杂平衡所产生的电子、自旋和轨道自由度的内在相互作用。这项工作将通过结合实验结果，化学键和分子轨道图来实现，为具有各种电子构型的过渡金属卤化物和氧化物的研究提供有价值的理论和实验输入。橡树岭国家实验室（ORNL）和路易斯安那州立大学材料科学科学家之间的合作工作将进一步支持拟议的计划。这项研究的结果可能会开辟一条通往量子磁性材料未知世界的道路。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。

Non-Technical description Quantum materials, in which the extraordinary effects of quantum mechanics can induce unique and unexpected behaviors, are the key to revolutionizing the future energy and information technologies. This proposal aims to establish a strong research program in inorganic materials at Louisiana State University (LSU) with the goal of addressing challenging issues to discover new quantum materials with exotic physical properties. By applying a fundamental understanding of the relationships among crystal structures, physical properties, and chemical bonding, we will synthesize and characterize novel quantum materials with the goal of understanding how magnetic properties are related to their chemical composition and atomic structure. This fellowship will provide a unique opportunity for the PI to learn neutron diffraction techniques at Oak Ridge National Laboratory (ORNL). This will allow for a new direction in materials research at LSU with a focus on finding new quantum materials from a chemistry perspective and facilitating interdisciplinary study of quantum materials in physics and chemistry. Technical descriptionTo date, the importance of spin-orbit coupling (SOC) to generate the electronic ground state in 4d/5d-based compounds have emerged and many novel routes to a variety of unconventional physical states have been revealed. For example, like quantum materials, like quantum spin liquids, Weyl semimetals, and axion insulators, which have strong spin-orbit coupling may have applications in data storage and memory, electronics, and quantum computing. This project aims to design, synthesize, and characterize molecule-based inorganic 4d/5d transition metals halides with the goal of understanding how magnetic properties are related to their chemical composition and atomic structure, and of facilitating technological applications over time. Currently, major experimental and theoretical efforts have been solely undertaken to search for novel spin-orbit coupling systems in various d5 systems where S=1/2. We will investigate structure-magnetism interactions and understand the intrinsic interplay of electronic, spin, and orbital degrees of freedom arising from a complex balance of electron-electron correlations (U), spin-orbit coupling (SOC), and crystal-field theory (CFT). This effort will be achieved by combining experimental results, chemical bonding and molecular orbit diagrams to provide valuable input to both theory and experimentation in the study of transition metal halides and oxides with various d electronic configurations. The collaborative work among scientists at Oak Ridge National Laboratory (ORNL) and LSU in materials science will further support the proposed program. The outcome, of this research could open a route into an uncharted world of quantum magnetic materials.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.