ISSN:
1573-4889
Keywords:
Oxidation
;
iron nitride
;
iron oxide
;
high-resolution transmission electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Oxide layers formed on varepsilon -Fe2N1-x wereinvestigated with X-ray photoelectron spectroscopy, X-ray diffraction, andin particular with high-resolution transmission electron microscopy. Priorto oxidation, the varepsilon -Fe2N1-x substrates wereeither exposed to air at room temperature, or subjected to asputter-cleaning pretreatment, or to a sputter cleaning with an additionalannealing pretreatment. The samples were oxidized at 400 or 573 K in pureO2 at 8.0x10-2 Pa or at 105Pa. All oxide films contained magnetite (ɛ -Fe2N1-x)as a major constituent. On samples that were sputter-cleaned and annealedprior to oxidation as well as on the air-exposed sample, wüstite,(Fe1-δO) was observed between the Fe3O4and ɛ -Fe2N1-x. On the basis of HREM, thiswüstite phase, which on α-Fe does not develop at temperaturesbelow 843 K, was concluded to have a preferred crystallographic orientationwith respect to the supporting ɛ -Fe2N1-x grains. Nospecific orientation relation was found between Fe3O4 andɛ -Fe2N1-x. The implications of the developmentof Fe1-δO for the evolution of the oxide film arediscussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004547100725
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