Structural-chemical transformations of alpha -Fe sub(2)O sub(3) upon transport reduction

Transient regions between iron oxide crystalline phases were found in various stages of alpha -Fe sub(2)O sub(3) structural-chemical transformation into FeO by Moessbauer spectroscopy. Particle sizes in those regions are less than 8 nm. The sequence of phase transformations was established for alpha...

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Bibliographic Details
Published in:Solid state ionics 2000-08, Vol.133 (3), p.203-210
Main Authors: Murin, I V, Smirnov, V M, Voronkov, G P, Semenov, V G, Povarov, V G, Sinel'nikov, B M
Format: Article
Language:English
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Summary:Transient regions between iron oxide crystalline phases were found in various stages of alpha -Fe sub(2)O sub(3) structural-chemical transformation into FeO by Moessbauer spectroscopy. Particle sizes in those regions are less than 8 nm. The sequence of phase transformations was established for alpha -Fe sub(2)O sub(3) reduction to iron at temperatures higher and lower than the wustite stability point (approximately 570 degree C). Two phases Fe sub(1-x)O and FeO were found to form upon the reduction within the wustite stability region (the stoichiometric phase is formed first). It was shown that reduction of hematite into magnetite occurs within temperature range 570-600 degree C by the multistage mechanism, while magnetite reduction to wustite occurs by a zonal mechanism, where three phases Fe sub(3)O sub(4), FeO and Fe are present in a sample simultaneously.
ISSN:0167-2738