Collaborative Research: RUI: Patterned Doping of Layered Materials

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Non-Technical Abstract: The research team has developed a method to incorporate impurities into layered materials, such as graphite, on the micrometer and nanometer scale. These impurities modify the physical, electronic, and optical properties of the layered materials. These properties have applications in solar cells, light emitting diodes (LEDs), and quantum computers to name a few. The ability to control impurities at the nanometer scale enables scientists and engineers to reduce the size of current devices, and possibly even discover new applications. The goal of this research is to use a multidisciplinary approach to obtain a more complete understanding of these samples. The University of Northern Iowa leads the fabrication efforts of impurity samples as well as characterization of their physical and electronic properties. Optical properties will be characterized at Texas Tech University. This research involves undergraduate students trained on a wide variety of techniques and technologies. Such an environment results in well-rounded students ready for careers in either industry or academia. As a leader in K-12 education, the University of Northern Iowa provides an excellent opportunity for this project to have a positive impact on elementary, middle, and high school students from diverse backgrounds. Regular contact with high school science teachers allows faculty research activities and student opportunities to be showcased directly. Such efforts encourage students to explore careers in STEM (science, technology, engineering, and mathematics) fields. Technical Abstract: Layered crystals exhibit a rich variety of phases such as magnetism, spin-glass behavior, superconductivity, and charge density waves. These phases can occur naturally in pure systems or be induced, disrupted, or modified via doping. Intercalation is a form of doping, in which atoms or molecules are inserted between the molecular layers. The research team has discovered a new method to locally intercalate layered crystals using a focused high energy electron beam. The goal of this research is to explore the ability to control phases in layered crystals on the micrometer and nanometer scale. The ability to create localized phase changes permits an exploration of a range of boundary conditions between different electronic or magnetic phases, as well as tunneling between them. This technique can be used in finite layer systems to reduce interlayer coupling and perhaps create new opportunities for entirely new two-dimensional behaviors.The collaborative effort between the University of Northern Iowa and Texas Tech University has the combined capabilities of atomic force microscopy, scanning tunneling microscopy, and Raman spectroscopy to characterize the local physical, electrical, and optical properties of these materials. The PIs work with a diverse group of research assistants and attract undergraduates from a variety of backgrounds and majors. An additional benefit of this collaborative work is the opportunity for undergraduate students from Iowa to work with graduate students from Texas Tech University. Lubbock, TX, has a very different culture and population than Cedar Falls, IA, which will benefit all students in learning to work with individuals from diverse backgrounds as is necessary in modern research.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.