MRI/RUI: Acquisition of Instrument Suite for Single Crystal Preparation

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This award is for the acquisition of a suite of instruments to prepare single crystals of intermetallic compounds by flux growth. Flux growth is a powerful technique that can produce high-quality single crystals of a wide variety of both congruently melting and incongruently melting compounds. The instruments include an arcmelter to alloy metals prior to growth, a tube furnace to grow crystals at higher temperatures, a box furnace to grow crystals at lower temperatures, saws and polishers to prepare crystals for measurement, a vacuum annealing furnace to anneal prepared samples, a microscope with digital camera, and a precision balance. The resulting crystals will be characterized using other NSF-funded instruments already at Grinnell College. A powder X-ray diffractometer provides structural information, while a Quantum Design PPMS-9 Physical Properties Measurement System provides anisotropic dc magnetization, ac susceptibility, resistivity, magnetoresistivity, and heat capacity data. These instruments support a long-standing collaborative research effort pursued by the principal investigator, undergraduates at Grinnell, and investigators at Ames Laboratory. Examples of collaborative research projects that the single crystal preparation instrument suite will support include studies of magnetic anisotropy in rare earth intermetallic single crystals and the design of a strongly anisotropic spin glass in single crystal form, used as a model system for testing spin glass theories. Because research is always blended with teaching at Grinnell, the single crystal preparation instruments will have broad impact beyond the research projects that they support. Students will use these instruments in collaborative research with the principal investigator, faculty-mentored independent student projects, and experiments in upper-level courses taken by physics majors. Grinnell College has a large, successful physics program, graduating 10 to16 physics majors per year, over half of whom go on to graduate school in science or engineering. Grinnell College has attained national recognition for its successful efforts to increase the retention of underrepresented groups in science through programs such as the New Science Project. The single crystal preparation instrument suite will help to broaden the exposure of these under-represented groups to research-quality instrumentation in their education and research training.