Abstract
The fully-oxidized surface that forms on (1 1 1) oriented Ni3Al single crystals, with and without Pt addition, at 300-900 K under oxygen pressures of ca. 10-7 Torr was studied using XPS, AES, and LEIS. Two main types of surfaces form, depending upon oxidation temperature. At low-temperature, the predominant oxide is NiO, capped by a thin layer of aluminum oxide, which we refer to generically as AlxOy. At high-temperature (i.e., 700-800 K), NiO is replaced by a thick layer of AlxOy. By comparing samples that contain 0, 10 and 20 at.% Pt in the bulk, we find that the effect of Pt is to: (1) reduce the maximum amount of both NiO and AlxOy; and (2) shift the establishment of the thick AlxOy layer to lower temperatures. Platinum also decreases the adsorption probability of oxygen on the clean surface.
Original language | English |
---|---|
Pages (from-to) | 146-154 |
Number of pages | 9 |
Journal | Surface Science |
Volume | 601 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2007 |
Externally published | Yes |
Funding
This work was supported by the Director, Ames Laboratory, U.S. Department of Energy, Contract No. W-405-Eng-82.
Funders | Funder number |
---|---|
U.S. Department of Energy | |
Ames Laboratory |
Keywords
- Aluminum oxide
- Auger electron spectroscopy
- Low-energy ion scattering (LEIS)
- Nickel aluminide
- Nickel oxides
- Oxidation
- Platinum
- X-ray photoelectron spectroscopy