Microscopic Dynamics in Metallic and Semiconducting Amorphous Systems Detected by NMR

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9802101 Wu This is a condensed matter physics research project in microscopic dynamics in metallic and semiconducting amorphous systems with high degrees of local order that are on the verge of forming nanocrystalline phases. Materials being studied include a newly discovered zirconium-titanium-copper-nickel-beryllium bulk metallic glasses, as well as highly ordered hydrogenated amorphous silicon made by hot filament assisted chemical vapor deposition. The main tool of investigation is nuclear magnetic resonance (NMR) which probes structural dynamics at the atomic level. Of interest is the rate of structural relaxation and other atomic motion toward equilibrium, especially below the calorimetric glass transition temperature, Tg, in the metallic glass. The diffusion dynamics of hydrogen in amorphous silicon is a long standing problem that will also be addressed. The materials in this project have important applications including micromachines and solar energy. The research involves quantum mechanics, computer simulations and laboratory skills in electronics and low temperature physics. The project trains under graduate and graduate students in a range of techniques in physics, material science, computer simulation, experimental skills, and communication skills with other scientists. %%% This research project in condensed matter physics deals with atomic-level motion in metallic and semiconducting amorphous systems that are on the verge of "freezing" into nanocrystalline solids. The main experimental tool is nuclear magnetic resonance (NMR) which is particularly appropriate for detecting the slow atomic motions accompanying the phase behavior. Materials being studied include newly discovered zirconium-titanium-copper-nickel- beryllium bulk metallic glasses, as well as highly ordered hydrogenated amorphous silicon made by hot filament assi sted chemical vapor deposition. These materials have important applications including micromachines and solar energy. The research involves quantum mechanics, computer simulations and laboratory skills in electronics and low temperature physics. The project trains under graduate and graduate students in a range of techniques in physics, material science, computer simulations, experimental skills, and communication skills with other scientists. ***