Electronic and Atomistic Effects in Nanostructures

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****Technical Abstract****This project is a study of the atomic-scale structure and behavior of composite systems that are prepared by atomic deposition, artificial layering, and thermal processing of metals on the most important electronic substrate materials, including silicon, germanium, and silicon carbide, that are flat, stepped, or decorated by atomic wires. The deposited metals, amounting to few atomic layers thick, tend to self-organize into nanoscale features, such as atomic wires, stripes, mesas, pyramids, or even ultrasmooth films, because of quantum confinement and boundary effects. These nanostructures often exhibit unusual properties that are not intuitively connected to the behavior of the metals in the bulk form. The underlying nanoscale science is a key basis for developing new material and device configurations relevant to technological and industrial advances. The research will focus on the connections between the stability, shapes, and sizes of the nanostructures and the electronic structure and chemical properties of the system, with the intent to derive a general understanding and design rules for guiding system fabrication and functionalization. The experimental tools will include angle-resolved photoemission spectroscopy and x-ray diffraction, and much of the work will be performed at national synchrotron-radiation facilities. This research bridges basic science and applications, and provides opportunities for education and training of students, postdoctoral research associates, and visiting scholars in the use of modern tools for materials synthesis and characterization. The experiences will position them well for careers in scientific research, education, technology, and industry.****Non-Technical Abstract****This project is a study of the atomic-scale structure and behavior of composite systems prepared by atomic deposition, artificial layering, and controlled heat treatment of metals on the most common electronic substrate materials including silicon, germanium, and silicon carbide. The deposited metals, amounting to few atomic layers thick, tend to naturally develop nanoscale features such as atomic wires, stripes, mesas, pyramids, or even ultrasmooth films. These nanostructures often exhibit unusual properties that are not observed in the bulk form of these materials. The underlying nanoscale science is a key basis for developing new materials and device configurations for industry. The research will focus on the connections between the stability, shapes, and sizes of the nanostructures and the electronic structure and chemical properties of the system, with the intent to derive a general understanding and design rules to guide the development of new functional materials. The experiments will be performed at national synchrotron radiation facilities, which provide intense x-rays for probing the systems of interest. This research bridges basic science and applications, and provides opportunities for education and training of students, postdoctoral research associates, and visiting scholars in the use of modern tools for materials synthesis and characterization. The experiences will position them well for careers in scientific research, education, technology, and industry.