1 / 7

Summary of Previous Results

Summary of Previous Results. Atom probe experimentation Atomic scale measurement of gas-solid reactions of Al and Oxygen Compound formation Study of Interfacial chemistry -3D interface analysis of gas solid reactions - Iso surface concentrations

Télécharger la présentation

Summary of Previous Results

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Summary of Previous Results • Atom probe experimentation • Atomic scale measurement of gas-solid reactions of Al and Oxygen • Compound formation • Study of Interfacial chemistry • -3D interface analysis of gas solid reactions - Iso surface concentrations • -Interfacial chemistry, morphology, etc. • Atomic scale measurement of gas-solid reactions of Si and oxygen • Refinements in Environmental chamber set up for in-situ gas reactions • Collaborations: • Maryland – Sample prepared by Maryland by reacting Si microtips; analysis of samples by ISU • Van Duin group – Use of atom probe results for experimental inputs into ReaxFF simulations

  2. Atom Probe Data for ReaxFF • - Original AP data • Data required for ReaxFF • Modifications • Future Steps • Gas solid reactions of near space environment condition • Surface reactions / orientation dependence of reactions

  3. Chemistry of Gas-Solid Reactions We have analyzed gas-solid reactions of materials and the resulting bonds • Oxidation of Aluminum at 450 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.

  4. Interface from Gas-Solid Reactions Measurement of two dimensional interfaces. Bulk Al2O3 phase Bulk Al phase Interface Interface shown from reaction of O and Al. Identify Al2O3 as bulk phase of gas-solid reaction, and perovskite phase at the interface. We have further developed this approach to imaging of 3D interfaces.- Interface shape- Interface uniformity

  5. Iso surface-Al (41%) Iso surface-Al (80%) Al (97%) O (1.93%) Image of changing interfacial isosurfaces with changing interfacial chemistry. Interface is uniform, and the shape of interface does not change significantly with chemistry.

  6. Atom Probe Data Range File Number=11 Ion1=Al Ion2=O Ion3=H …… [Ranges] Number=23 Range1=13.3740 13.8830 Vol:0.01661 Al:1 Color:33FFFF Range2=8.9770 9.2620 Vol:0.01661 Al:1 Color:33FFFF Range3=26.8780 27.4970 Vol:0.01661 Al:1 Color:33FFFF Range4=15.8811 16.4270 Vol:0.02883 O:1 Color:6666FF Range5=7.9460 8.1220 Vol:0.02883 O:1 Color:6666FF Range6=1.0000 1.0830 Vol:0.00000 H:1 Color:CCCC00 Range7=2.0020 2.0400 Vol:0.00000 H:2 Color:FF0000 Range8=21.3820 21.9550 Vol:0.04543 Al:1 O:1 Color:FF3333 Range9=42.8450 43.5160 Vol:0.04543 Al:1 O:1 Color:FF3333 Range10=23.2730 23.5960 Vol:0.06204 Al:2 O:1 Color:00FF00 ------------- POS file mass = 70 and charge=3 resulting in m/n peak in range of 23.2 - 23.5.  Range10=23.2730 23.5960 Vol:0.06204 Al:2 O:1 Color:00FF00  

  7. AP Data ReaxFF Data Al 4.00948 4.81846 36.33220 1Al 0.27611 4.06606 32.27097 1Al 6.66427 45.77823 34.90955 1 O Al All the compounds were identified and selected from the POS file Compound ions converted into respective constituent ions at a given position

More Related