ISSN:
1573-4889
Keywords:
AES
;
Fe(poly)
;
sulfur
;
aluminum oxide
;
reduction
;
interface
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Auger measurements reveal that, under UHV conditions, interfacial sulfurinduces the destabilization of an aluminum oxide overlayer at theFe–Al2O3 interface at temperatures above400 K. One monolayer deposition of Al onto Fe/S results in the insertion ofAl at the Fe–S interface. Exposure of Fe–Al–S to oxygenat 300 K gives rise to the complete oxidation of the aluminum adlayer asevidenced by the disappearance of the Al0 Auger signal and thestoichiometric formation of the aluminum oxide. When the resultingFe–S–Al2O3 is annealed progressively tohigher temperatures between 400 and 900 K, analysis of the Auger spectrashows a dramatic decline in the Al/O Auger intensity ratio. This declineis accompanied by the appearance of a small signal due to Al0,which maintains a constant intensity as the total Al signal (due mainly toAl3+) decreases. The appearance of the Al0 Augersignal accompanied by the attenuation of the Al3+ signalsignifies the chemical conversion of Al3+ into Al0,probably followed by diffusion of Al into the bulk. The possibility ofalumina dewetting and island formation, however, cannot be ruled out onthe basis of the present data. In the absence of interfacial sulfur, the alumina–Fe interface is stable to 900 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004602412849
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