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ISU Updates. Rupa Dumpala , Scott Broderick, Joaquin Peralta and Krishna Rajan Feb 12, 2013. Summary of Previous Results. Oxidation of Aluminum at 723 K C, 2.5 x 10- 3 Torr for 10 min.
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ISU Updates • RupaDumpala, Scott Broderick, Joaquin Peralta and Krishna Rajan Feb 12, 2013
Summary of Previous Results • Oxidation of Aluminum at 723 K C, 2.5 x 10-3Torr for 10 min. • The Al-O compounds shown are from an Al2O3 phase. By measuring the compounds, we get a more local chemical measurement – Al2O3 phase comprised of Al2O, Al2O2, AlO and AlO2 clusters • Interface shown from reaction of O and Al. Identify Al2O3 as bulk phase of gas-solid reaction • We have further developed this approach to imaging of 3D interfaces (iso-surface).- Interface shape- Interface uniformity • Atom probe data was converted to suitable form for ReaxFF simulations
Si and Oxygen System at 373 K Si O SiO2 SiO Si2O O2
Si and Oxygen System at 373 K Si2O SiO O SiO2 Si O SiO2 SiO Si2O Pure Si, SiOx (x < 2), and SiO2 phases is indicated in the histograms by light gray bars, green bars, and red bars, respectively. • Inward and outward growth of Si, SiOx (x < 2) and only outward growth of SiO2
Si and Oxygen System at 548 K Si O SiO2 SiO Si2O O2
Si and Oxygen System at 548 K Si2O SiO O SiO2 Si O SiO2 SiO Si2O Pure Si, SiOx (x < 2), and SiO2 phases is indicated in the histograms by light gray bars, green bars, and red bars, respectively. • Inward and outward growth of Si, SiOx (x < 2) and only outward growth of SiO2
Study of Interfaces 548 K 373 K 2.6 nm 1.8 nm 700 K 300 K • Increase of interface thickness with the temperature was noticed similar to simulation results
Future Steps • Analysis of Al and oxygen system with varying temperature similar to silicon system • Gas solid reactions of near space environment condition • Surface reactions / orientation dependence of reactions