updates of iowa state university
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Updates of Iowa State University . S. Dumpala , S. Broderick, A. J. Peralta and K. Rajan Mar – 11 - 2013 . Summary of Previous Al oxidation results. Oxidation of Aluminum at 450 C, 2.5 x 10- 3 Torr for 10 min. - PowerPoint PPT PresentationTRANSCRIPT
Updates of Iowa State University
S. Dumpala, S. Broderick, A. J. Peralta and K. Rajan
Mar – 11 - 2013
• Oxidation of Aluminum at 450 C, 2.5 x 10-3 Torr for 10 min.
• Interface shown from reaction of O and Al. Identify Al2O3 as bulk phase of gas-solid reaction
• Use of AP results for experimental inputs into ReaxFF simulations
Summary of Previous Al oxidation results
Diffusion Profiles - APT
Environmental Chamber- APT
• Heater stage preheated to 500 C (sample T-300 C)
• Pressure – 7x 10 -5 torr for 5 min
• APT – Laser run at 1 nj
• Different oxygen species are detected as observed earlier
Present - Al oxidation results
Study of InterfacesDiffusion Profiles - APT
Al
O
Al- Iso surface 95.23%
• Oxidation forming – AlO phase compared to stoichiometric Al2O3 phase observed earlier
• Different oxide species observed
Bulk Al2O3 phase Bulk Al phase
Al
O
• XPS, HRTEM also reported formation of limiting thickness Al-deficient phase than Al2O3 at <573 K [1]
• The observed formation of stoichiometric Al2O3 phase at higher temperature is consistent with ref [1] for temperature 773 K
• The thickness shown to increase with increasing temperature [1] also consistent with APT results.
[1] Jeurgesn L.P.H., et. al., J. App. Phys. 2002, 92, 1649
Bulk Al phase
AlO
573 K 723 K
Effect of Temperature
Future
• More experiments as function of temperature and pressures
• Study of oxidation mechanism
• Testing the Si tips from Maryland