Acquisition of Electron and X-Ray Diffraction Equipment for Oxide Superlattice Research and Education

这一行动为购置高压反射高能电子衍射（RHEED）系统和用于氧化物超晶格研究和教育的四圆X射线衍射系统提供了资金。电子衍射仪器将改造现有的脉冲激光沉积（PLD）系统，以允许实时，在单层，单位细胞水平的薄膜生长的原位测定。在多个目标之间切换允许氧化物超晶格薄膜在不同组成的层之间形成原子级尖锐的界面。X射线衍射仪将用于非原位测定超晶格的晶体结构和扭曲，包括晶格对应、应变失配和层间原子混合。利用该系统生长出的高质量氧化物超晶格将为科学和技术发展提供新的机遇。超晶格可以被设计为在界面处触发竞争相互作用，诱导先前不存在于氧化物成分中的离子、电子和磁激发模式，并且设计堆叠相关的对称性破缺以克服组成晶体的对称性约束。简而言之，具有人工纳米级设计的新材料成为可能。这些材料有望显示出增强的场响应和奇异的非线性特性，可用于电，磁和光学应用。预计将对材料物理学产生重大影响，特别是对过渡金属氧化物磁性，导电性和铁电性的基本理解。我们的教育计划成功地指导了高质量的博士和博士后研究人员，同时为本科生和高中教师提供培训。这项工作将被纳入研究，以吸引学生，并为他们提供实验室和研究经验。此次收购将加强提供原子级制造，表征和可视化体验的能力，这对年轻学生来说是最令人兴奋，最具吸引力和教育意义的。通过与一家初创的计算机存储器公司进行持续的协作、协同和探索性研究，将进一步扩大与工业界的联系。

This action provides funds for the acquisition of a high pressure Reflection High-Energy Electron Diffraction (RHEED) system and a four-circle X-ray diffraction system for oxide superlattice research and education. The electron diffraction instrument will be retrofit to an existing pulse laser deposition (PLD) system to allow real-time, in-situ determination of film growth at the single layer, unit cell level. Switching between multiple targets allows oxide superlattice thin films to form with atomically sharp interfaces between layers of different compositions. The X-ray diffraction instrument will be used for ex-situ determination of the crystal structures and distortions of the superlattices, including lattice correspondence, strain misfit, and interlayer atomic mixing. High quality oxide superlattices grown by this system will provide new scientific and technological opportunities. The superlattices can be designed to trigger competing interactions at the interface, induce ionic, electronic and magnetic excitation modes not previously present in the oxide constituents, and engineer stacking-related symmetry breaking to override the symmetry constraint of the constituent crystals. In short, essentially new materials with an artificial, nanoscopic design become possible. These materials are expected to show enhanced field responses and exotic non-linear properties that can be used for electrical, magnetic, and optical applications. A large impact is expected on the materials physics, especially on the fundamental understanding of transition-metal-oxide magnetism, conductivity and ferroelectricity.Our educational program has been successful in mentoring high quality PhDs and postdoctoral researchers while offering training to undergraduates and high school teachers. This effort will be integrated into the research to attract students and to provide them with laboratory and research experience. The acquisition will strengthen the capability to offer atomic-scale fabrication, characterization, and visualization experience, which has proved most exciting, inviting, and educating to young students. Further outreach to industry will be made through ongoing collaborative, synergistic, and exploratory research with a start-up computer memory company.