Conversion Processing of Functional Oxides to Oxyfluorides

复合氧化物在支持现代社会的广泛技术中发挥着关键作用，在能源，通信和健康领域中具有应用。制造这些材料薄膜的能力将使电子和能量转换的新应用成为可能。然而，为了充分利用氧化膜的潜力，需要新的加工方法，这将使更广泛的材料组合物被制造。该奖项支持基础研究，重点是开发和理解氟受控取代氧的策略，从而实现新的手段来设计薄膜和纳米材料的电子，光学和磁性。待研究的处理方法是可扩展的，需要最少的资本投资，并且可以在广泛的氧化膜上进行，而与材料最初的处理方式无关。因此，该研究将直接支持国家的战略目标，即开发敏捷的材料加工新方法，以减少从材料发现到技术部署的时间。该研究还将通过为参与学生的高级工程教育做出贡献而使美国经济受益。虽然沉积技术的进步已经使钙钛矿氧化物薄膜的加工具有单层精度，但扩大对新材料化学的使用仍然是一个挑战。该项目的重点是氟取代氧，这使得控制过渡金属阳离子的价态和金属阴离子键的共价性，这两种效应对电子，铁电和光学性质具有深远的影响。本研究将阐明基于氧化膜生长后转化反应合成氟氧化物混合阴离子钙钛矿的基本科学机理。待研究的转化过程利用含氟聚合物的蒸气传输和阴离子扩散。该团队将存款氧化膜，进行反应，并利用光谱和结构表征技术，以开发一个预测性的理解如何得到的阴离子组合物可以通过加工条件来调整功能特性。

Complex oxides play a critical role in wide-ranging technologies that underpin modern society with applications in the energy, communications, and health sectors. The ability to make thin films of these materials will enable new applications in electronics and energy conversion. However, in order to fully harness the potential of oxide films, new processing approaches are required that will enable a wider range of material compositions to be manufactured. This award supports fundamental research focused on developing and understanding strategies for the controlled substitution of fluorine for oxygen, thereby enabling new means to engineer electronic, optical, and magnetic properties of thin films and nanomaterials. The processing methods to be studied are scalable, require minimal capital investment, and can be carried out on a broad range of oxide films, independent of how the materials were first processed. As such, the research will directly support the nation's strategic goal of developing agile new approaches for materials processing that can reduce the time from material discovery to technological deployment. The research will also benefit the U.S. economy by contributing to the advanced engineering education of the participating students. While advances in deposition techniques have enabled the processing of perovskite oxide films with monolayer precision, expanding access to new material chemistries remains a challenge. This project is focused on the substitution of fluorine for oxygen, which allows for control of the transition metal cation valence state and the covalency of the metalanion bond, both effects having profound implications for electronic, ferroic, and optical properties. This research will elucidate fundamental scientific mechanisms in the synthesis of oxyfluoride mixed-anion perovskites based on post-growth conversion reactions of oxide films. The conversion processes to be studied utilize vapor transport and anion diffusion from fluoropolymers. The team will deposit oxide films, carry out fluorination reactions, and utilize spectroscopic and structural characterization techniques to develop a predictive understanding of how the resultant anion composition can be engineered through processing conditions to tune functional properties.