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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/9915

Title: Effects of precursor chemistry and thermal treatment conditions on obtaining phase pure bismuth ferrite from aqueous gel precursors
Authors: HARDY, An
Gielis, S.
VAN BAEL, Marlies
Issue Date: 2009
Citation: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 29(14). p. 3007-3013
Abstract: Phase pure BiFeO3 powders are synthesized by an entirely aqueous solution-gel route, starting from water soluble Fe(III) nitrate or citrate, and Bi(III) citrate as precursors. In order to obtain stable solutions, which transform to homogeneous gels upon drying, the pH is adjusted to 7 and a citric acid content equimolar to the metal ions is selected. The presence of nitrate strongly accelerates the thermo-oxidative decomposition step of the precursor gel around 200 degrees C, and the decomposition is finished at a lower temperature for the nitrate containing precursor (460 degrees C) than without nitrates (500 degrees C) in dynamic dry air. An oxidative ambient is required to fully decompose the precursor. The presented synthesis allows very low temperature (400 degrees C) crystallization of BiFeO3 together with a secondary phase, as shown by high temperature XRD. This parasitic phase remains up to high temperatures, where decomposition of BiFeO3 is observed from 750 degrees C onwards, and Bi2Fe4O9 is formed. However, optimization of the furnace treatment, considering anneal temperatures and heating rates showed that phase pure BiFeO3 can be obtained, with the heating rate being the crucial factor (5 degrees C/min). The chemical purity of the powders is confirmed by FTIR, and the antiferromagnetic to paramagnetic phase transition is demonstrated by DSC measurements. (C) 2009 Elsevier Ltd. All rights reserved.
Notes: [Hardy, A.; Gielis, S.; Van den Rul, H.; Van Bael, M. K.; Mullens, J.] Hasselt Univ, Lab Inorgan & Phys Chem, Inst Mat Res, B-3590 Diepenbeek, Belgium. [Hardy, A.; Van den Rul, H.; D'Haen, J.; Van Bael, M. K.] IMEC VZW, Div IMOMEC, Diepenbeek, Belgium. [Hardy, A.] XIOS Hogesch Limburg, Dept Appl Engn Sci, Diepenbeek, Belgium. [D'Haen, J.] Inst Mat Res, B-3590 Diepenbeek, Belgium.
URI: http://hdl.handle.net/1942/9915
DOI: 10.1016/j.jeurceramsoc.2009.05.018
ISI #: 000269139600013
ISSN: 0955-2219
Category: A1
Type: Journal Contribution
Validation: ecoom, 2010
Appears in Collections: Research publications

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