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

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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.