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

对于许多材料系统，界面处的性质对性能至关重要。用于低功率电子材料、逻辑器件和磁电机的纳米结构材料，可用作传感器和局部能量收集器，为低成本、高性能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（CAREER）奖支持研究，以了解和控制纳米结构功能材料的构建模块。本研究旨在揭示控制原子尺度有序化和局域输运机制的机制，并开发调节它们的方法。这项工作的研究和教育部分将使原子世界的对称性可见-通过参与小学教师的外展计划，研究人员将通过使用全息术的交互式可视化活动介绍原子对称性的概念。单晶纳米氧化物中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，主要是八面体畸变。在这项工作中，单晶氧化物进行自组装，形成一个超结构的棋盘图案的纳米尺寸的域进行了研究，以阐明自组装的机制。这些材料在各种机械边界条件下的外延生长提供了对超结构的控制，从而控制了性能。独特的参数是不可用于批量处理允许传输机制的基本原理的理解，也允许调谐和不同类型的传导隔离，导致亚稳态结构，并揭示低维的传导路径。这个奖项反映了NSF的法定使命，并已被认为是值得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的支持。

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.