CAREER: Controlled Processing of Self-Assembly in Single Crystal Oxide Films

对于许多材料系统，界面处的性能对性能至关重要。纳米结构材料用于低功率电子材料、逻辑器件和巨型电子器件，用作传感器和局部能量收集器，为开发低成本、高性能的材料和器件提供了潜力。这些材料和设备有许多应用，包括国家安全和国防。为了更好地了解如何设计这些材料，该学院早期职业发展计划(CALEAR)奖支持了解和控制纳米结构功能材料的构建块的研究。这项研究试图揭示控制原子尺度有序和局部传输机制的机制，并开发调整它们的方法。这项工作的研究和教育部分都将使原子世界中的对称性变得可见-通过邀请小学教师参与的外联计划，研究人员将通过使用全息的交互式可视化活动引入原子对称性的概念。单晶纳米级氧化物的自组装的起源是一个争论的主题，并被归因于成分和结构的变化，主要是八面体扭曲。在这项工作中，单晶氧化物经过自组装形成了棋盘状纳米结构的超结构，以阐明自组装的机制。这些材料的外延生长具有不同的机械边界条件，从而提供了对超结构和性能的控制。这一奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，认为值得支持。

For a number of materials systems, the properties at the interfaces are critical to performance. Nanostructured materials for low power electronic materials, logic devices, and megnetoelectrics, which are used as sensors and local energy harvesters, offer the potential for low-cost, high-performance materials and devices. These materials and devices have numerous applications, including national security and defense. To better understand how to engineer these materials, this Faculty Early Career Development Program (CAREER) Award supports research to understand and control the building blocks for nanostructured functional materials. This research seeks to reveal the mechanisms controlling atomic-scale ordering and local transport mechanisms, and developing the means to tune them. Both the research and education components of this work will make symmetry in the atomic world visible - through outreach programs engaging elementary school teachers, the researchers will introduce concepts of atomic symmetry though interactive visualization activities using holography.The origin of the self-assembly in single crystal nanoscale oxides is a subject of debate and has been attributed to both compositional and structural variations, mainly octahedral distortions. In this work, single crystal oxides which undergo self-assembly to form a superstructure in a checkerboard pattern of nanometer-sized domains are investigated to elucidate the mechanisms of self-assembly. Epitaxial growth of these materials with various mechanical boundary conditions provides control over the superstructure and thus the properties. Unique parameters that are not available in bulk processing allow understanding of the fundamentals of transport mechanisms, and also allow tuning and isolation of different types of conduction, leading to metastable structures, and revealing lower-dimensional conduction paths.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.