The effect of Pt on Ni3Al surface oxidation at low-pressures

TitleThe effect of Pt on Ni3Al surface oxidation at low-pressures
Publication TypeJournal Article
Year of Publication2007
AuthorsQin F, Anderegg JW, Jenks CJ, Gleeson B, Sordelet DJ, Thiel PA
Journal TitleSurface Science
Volume601
Pages146-154
Date PublishedJan
Type of ArticleArticle
ISBN Number0039-6028
Accession NumberISI:000243655000018
Keywordsaluminum oxide, ALUMINUM-OXIDE OVERLAYER, Auger electron spectroscopy, low-energy ion scattering (LEIS), nickel aluminide, nickel oxides, oxidation, OXYGEN-ADSORPTIO, platinum, single-crystal surfaces, X-RAY PHOTOELECTRON, X-ray photoelectron spectroscopy
Abstract

The fully-oxidized surface that forms on (111) 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. (c) 2006 Elsevier B.V. All rights reserved.

DOI10.1016/j.susc.2006.09.014
Alternate JournalSurf. Sci.