Understanding Inorganic Solid State Reactivity for the Design of Functional Materials

固态金属氧化物因其特殊的功能多样性而被广泛用作功能材料，在微型化和高效器件的设计中发挥着至关重要的作用。这项提案要求为我的合成和表征研究项目提供资金，该项目涉及功能固态材料的定制设计。该计划特别关注扩展金属氧化物中的结构-反应性关系。我正在利用能够实时跟踪固态反应的原位衍射实验来开发合成策略。这种方法为我们的模型系统提供了反应方案，可以扩展到整个结构族。除了在合成过程中发现中间相外，我们还可以对这些材料进行淬火和分离。我目前的研究计划清楚地展示了丰富的亚稳态功能材料，这些材料是可以获得的，只有高温固态反应才会错过这些材料。我的重点是制备氧化物缺陷结构，作为固体氧化物燃料电池(SOFC)中的固体氧化物电解质。SOFC的工作温度接近1000°C，我们正在设计在较低温度下具有更高氧离子迁移率的材料。这些材料中空位有序和无序氧亚晶格的相互作用需要更深入地了解结构-反应关系、相变和材料在操作条件下的稳定性。利用与萤石相关的结构中的氧化还原活性金属，我们将实时研究氧化物空位的产生和湮灭以及它们的协同行为。此外，我们还将制备磁性材料，以产生自旋液体。通过化学和结构修饰引入磁矩之间的竞争相互作用，使我们能够探测一维、二维和三维晶格中的磁性相互作用。我们正在使用各种合成工具，包括低温拓扑定向反应(氟插入和固态氢化物还原)、高压合成、溶胶-凝胶和传统的高温固态制备。我们的高温原位衍射设备能够实时跟踪固态反应。在这些实验中可以清楚地观察到反应路径，结果使我们能够制备大块样品。我们对结构进行了详细的表征，并评估了它们的反应性和物理性质。更高级的研究是在同步加速器(APS，CLS)和中子设施(SNS，ILL，HFIR)上进行的，使用一套能够以高速率、高分辨率和高压跟踪反应的光束线。拟议的研究计划将为材料科学、化学和物理交叉学科的学生提供独特的培训机会，并为毕业生成为加拿大研究密集型经济的未来领导者做好准备。

Solid state metal oxides are widely used as functional materials due to their exceptional functional diversity and play vital roles in miniaturization and the design of highly efficient devices. This proposal requests funding for my synthesis and characterization research program concerned with the tailored design of functional solid state materials. The program has a unique focus on structure-reactivity relations in extended metal oxides. I am developing synthetic strategies using in-situ diffraction experiments capable of following solid state reactions in real time. This approach provides reaction schemes for our model systems that can be expanded to entire structural families. In addition to the discovery of intermediate phases during the synthesis we can quench and isolate those materials. My current research program clearly demonstrates the wealth of metastable functional materials that is accessible and would have been missed with high temperature solid state reactions only. I am focussing on the preparation of oxide defect structures for applications as solid state oxide electrolytes in solid state oxide fuel cells (SOFCs). SOFCs operate close to 1000°C and we are designing materials with higher oxide ion mobilities at lower temperatures. The interplay of vacancy ordered and disordered oxygen sublattices in those materials requires a deeper understanding of structure-reactivity relations, phase transitions and materials' stability under operating conditions. Using redox active metals in fluorite related structures we will investigate the creation and annihilation of oxide vacancies and their cooperative behaviour in real time. In addition we will prepare magnetic materials in order to generate spin liquids. Introducing competing interactions between magnetic moments through chemical and structural modifications allows us to probe magnetic interactions in 1, 2 and 3-dimensional lattices. We are using a wide variety of synthetic tools including low temperature topotactic reactions (fluorine insertion and solid state hydride reductions), high pressure synthesis, sol-gel and traditional high temperature solid state preparations. Our high temperature in-situ diffraction facility is capable of tracking solid state reactions in real time. Reaction pathways are clearly observable in those experiments and the results enable us to prepare bulk samples. We characterize structures in detail and evaluate their reactivities and physical properties. More advanced studies are carried out at synchrotron (APS, CLS) and neutron facilities (SNS, ILL, HFIR) using a suite of beamlines capable of following reactions at high rates, high resolution and high pressures. The proposed research program will provide unique training opportunities for students at the intersection of materials science, chemistry and physics and prepares graduates to be future leaders in Canada's research intensive economy.