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

Case Western Reserve University, Cleveland OH

Investigators

Abstract

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.