Chadwick, A.V. and Bruce, P.G. and Womes, M. and Harrison, A. and Jumas, J.C. and Jiao, F. (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. (Full text available)
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).
|Divisions:||Faculties > Science Technology and Medical Studies > School of Physical Sciences|
|Depositing User:||Alan Chadwick|
|Date Deposited:||23 Sep 2008 12:47|
|Last Modified:||15 Jan 2012 15:25|
|Resource URI:||http://kar.kent.ac.uk/id/eprint/8961 (The current URI for this page, for reference purposes)|