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

这一行动为购买高压反射高能电子衍射(RHEED)系统和四圈X射线衍射系统提供资金，用于氧化物超晶格研究和教育。电子衍射仪将改装成现有的脉冲激光沉积(PLD)系统，以便能够在单层、单元单元水平上实时、原位地确定薄膜的生长。多个靶之间的切换允许氧化物超晶格薄膜在不同成分的层之间形成原子锐利的界面。X射线衍射仪将用于非原位测量超晶格的晶体结构和变形，包括晶格对应、应变失配和层间原子混合。由该系统生长的高质量氧化物超晶格将提供新的科学和技术机会。超晶格可以被设计成在界面上触发竞争相互作用，诱导以前在氧化物成分中不存在的离子、电子和磁激发模式，并设计与堆积相关的对称破缺来超越组成晶体的对称约束。简而言之，具有人工纳米设计的本质上是新的材料成为可能。这些材料有望表现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。我们的教育项目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。这一努力将整合到研究中，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尺度的制造、表征和可视化体验的能力，事实证明，这对年轻学生来说是最令人兴奋、最具吸引力和最具教育性的体验。将通过与一家初创的计算机存储公司进行持续的合作、协同和探索性研究，进一步扩大到行业的范围。

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.