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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/11476

Title: Crystallization of alkaline earth zirconates and niobates from compositionally flexible aqueous solution-gel syntheses
Authors: HARDY, An
D'HAEN, Jan
VAN DEN RUL, Heidi
VAN BAEL, Marlies
MULLENS, Jules
Issue Date: 2009
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
Citation: MATERIALS RESEARCH BULLETIN, 44(4). p. 734-740
Abstract: Barium and strontium zirconates and niobates were prepared by means of an economic and ecologic aqueous solution-gel route with high compositional flexibility. The synthesis of precursor solutions and gels, and thermal analysis of the gels are presented. The crystallization of the different oxides was studied in situ using high-temperature X-ray diffraction measurements (HT-XRD). Zirconate crystallization was observed between 600 degrees C and 700 degrees C. Small amounts of Ba(II)- and Sr(II)-carbonate crystallized before the oxide did, and decomposed between 700 degrees C and 800 degrees C. More sensitive Fourier transform infrared spectra, showed that very small traces of carbonate remain at 900 degrees C. The crystallization behavior of strontium niobates was strongly dependent on the Sr:Nb ratios, as observed in HT-XRD. Phase pure SrNb2O6 was obtained at low temperature (600 degrees C). Sr2Nb2O7 and Sr5Nb4O15 were formed at 900 degrees C from an intermediate phase, with a minor secondary phase. Nb2Sr4O9 crystallized at 600 degrees C, but transformed to a mixture of phases at high temperature (1000 degrees C). By off-line furnace annealing, phase pure strontium niobates of all four compositions were obtained. The presented work demonstrates the high compositional flexibility of the aqueous solution-gel route, allowing fast synthesis of different multimetal oxides with high purity. (C) 2008 Elsevier Ltd. All rights reserved.
Notes: [Hardy, A.; Van den Rul, H.; Van Bael, M. K.; Mullens, J.] Hasselt Univ, Inorgan & Phys Chem Grp, Inst Mat Res, BE-3590 Diepenbeek, Belgium. [Hardy, A.] XIOS Hogesch Limburg, Dept IWT, Diepenbeek, Belgium. [Hardy, A.; D'Haen, J.; Van den Rul, H.; Van Bael, M. K.] IMEC, Div IMOMEC, Diepenbeek, Belgium. [D'Haen, J.] Hasselt Univ, Mat Phys Grp, Inst Mat Res, BE-3590 Diepenbeek, Belgium. an.hardy@uhasselt.be; marlies.vanbael@uhasselt.be
URI: http://hdl.handle.net/1942/11476
DOI: 10.1016/j.materresbull.2008.09.035
ISI #: 000264421200004
ISSN: 0025-5408
Category: A1
Type: Journal Contribution
Validation: ecoom, 2010
Appears in Collections: Research publications

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