Synthesis of ordered mesoporous Fe3O4 and gamma-Fe2O3 with crystalline walls using post-template reduction/oxidation

Chadwick, Alan V. and Bruce, Peter G. and Womes, Manfred and Harrison, Andrew and Jumas, Jean-Claude and Jiao, Feng (2006) Synthesis of ordered mesoporous Fe3O4 and gamma-Fe2O3 with crystalline walls using post-template reduction/oxidation. Journal of the American Chemical Society, 128 (39). pp. 12905-12909. ISSN 0002-7863. (doi:https://doi.org/10.1021/ja063662i) (Full text available)

Abstract

Ordered mesoporous Fe3O4 with crystalline walls (inverse spinel structure) has been synthesized for the first time, representing to the best of our knowledge, the first synthesis of a reduced mesoporous iron oxide. Synthesis was achieved by reducing ordered mesoporous alpha-Fe2O3 (corundum structure) to Fe3O4 spinel then to gamma-Fe2O3 by oxidation, while preserving the ordered mesostructure and crystalline walls throughout. Such solid/solid transformations demonstrate the stability of the mesostructure to structural phase transitions from the hexagonal close packed oxide subarray of alpha-Fe2O3 (corundum structure) to the cubic close packed subarray of Fe3O4 spinel and gamma-Fe2O3. Preliminary magnetic measurements reveal that the spins in both Fe3O4 and gamma-Fe2O3 are frozen at 295 K, despite the wall thickness (7 nm) being less than the lower limit for such freezing in corresponding nanoparticles (> 8 nm).

Item Type: Article
Projects: [40] ALISTORE
Subjects: Q Science
Divisions: Faculties > Sciences > School of Physical Sciences
Depositing User: Alan Chadwick
Date Deposited: 23 Sep 2008 12:47 UTC
Last Modified: 18 Jun 2014 10:53 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/8961 (The current URI for this page, for reference purposes)
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