Studies of Dynamic Material Interfaces in Extreme Environments
Technical Report,15 Sep 2015,14 Jun 2019
University Of Chicago Chicago United States
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The scattering of atomic and molecular beams from well-characterized surfaces is an incisive method for studying the dynamics of gas-surface interactions, providing precise information on energy and momentum transfer as well as complex reaction mechanisms. Scanning probe measurements provide a powerful complement to scattering data as SPM measurements give a direct route to the visualization and spectroscopic characterization of interfacial atomic and nanosystems. This AFOSR program examined critical aspects of the chemical and physical behavior of dynamic material interfaces operating in extreme environments. Extreme conditions encompass high and low temperature regimes, high velocity gas flows, optical and charged particle illumination, and severe oxidative environments where interfacial aerodynamic performance energy and momentum transfer characteristics, morphological change, and chemical stability need to be assessed and quantified. This grant has led to a period of notable discovery and productivity, with experiments complemented by commensurate theory and numerical simulations. We have examined The vibrational band structure of methyl-terminated Ge111, a promising new electronic interface The capture of CO2 by the recently discovered mechanism of energetic embedding The growth, structure, and vibrational properties of few layer graphene Inelastic collisional gassurface energy transfer involving molecular hydrogen Temporally and spatially-resolved oxidation of silicon and graphite using energetic supersonic molecular beams combined with scanning tunneling microscopy visualization of the reacting surface note that a key feature of our activities is to systematically map out site-specific reactivity and morphology changes on the atomicnanomesomicro length-scales to accompany our precision measurements of interfacial chemical kinetics.
- Atomic and Molecular Physics and Spectroscopy