"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."
Powder X-ray diffraction is one of the most powerful methods of characterizing the structures of solids and is fundamental to research across the physical sciences. Within the proposed project, a new diffractometer will be acquired and used by faculty and undergraduate students from the departments of chemistry and biochemistry, physics and astronomy, and geology at Oberlin College. This instrument will combine reliable collection of high-quality diffraction data for bulk powder samples with advanced capabilities for variable temperature, thin film, and small-angle X-ray scattering experiments. The diffractometer will impact a wide range of student-faculty research projects. Newly synthesized hybrid inorganic-organic materials with potential catalytic and hydrogen-storage applications will be identified and their structural changes probed as a function of temperature. Thin corrosion films formed by organic acid attack on lead-tin alloys will be analyzed as part of multidisciplinary research to understand the causes and mechanisms of historic organ pipe degradation. Nanostructured magnetic materials for data storage and biomedical applications will be characterized using both the X-ray diffraction and small-angle X-ray scattering capabilities of the instrument. X-ray diffraction of polycrystalline samples of small peptides will complement solution-state and solid-state NMR determination of their preferred, low-energy structures. Mineral polymorphs will be studied, providing insight into the geodynamics of the subduction zones from which they are extracted. In addition to providing training in advanced techniques to undergraduate research students, the instrument will be integrated into the intermediate and upper-level laboratory curricula in all three collaborating departments.
Many classes of commonly encountered materials ? including metals, polymers, and minerals ? have underlying structures made up of repeating patterns of atoms or molecules. Powder X-ray diffraction and related X-ray scattering techniques can determine the arrangements of these atoms on nanometer length scales. Knowledge of these structures is essential in developing new materials and applications as well as in understanding geologic and chemical processes through which materials change over time. Within the proposed project, a new powder X-ray diffractometer will be acquired and used by faculty and undergraduate students in the departments of chemistry and biochemistry, physics and astronomy, and geology at Oberlin College. The five principal investigators, including two faculty members hired within the last four years, have expertise in standard and specialized X-ray techniques. The new instrument will contribute to their research in the synthesis of new materials with magnetic, catalytic, and hydrogen-storage applications; the determination of the detailed structures of peptides ? some of the most basic biological materials; the understanding of the geological processes occurring in subduction zones; and the conservation of historic organ pipes that are damaged by atmospheric corrosion. The X-ray diffractometer will enhance ongoing efforts to integrate teaching and research at Oberlin. Undergraduate students engaged in research will receive training in contemporary, advanced techniques for materials characterization. The instrument will be used in laboratory coursework by all chemistry, physics, and geology majors, a diverse group including many students who go on to graduate school in the physical sciences.
