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http://hdl.handle.net/10773/20551
Title: | Enhanced BaZrO3 mechanosynthesis by the use of metastable ZrO2 precursors |
Author: | Sherafat, Z. Antunes, I. Almeida, C. Frade, J. R. Paydar, M. H. Mather, G. C. Fagg, D. P. |
Keywords: | DOPED BARIUM ZIRCONATE THERMAL-DECOMPOSITION STEAM ELECTROLYSIS MECHANOCHEMICAL SYNTHESIS MICROSTRUCTURAL CHANGES PHASE-TRANSFORMATIONS MECHANICAL ACTIVATION PROTON CONDUCTIVITY HYDROGEN-PRODUCTION CRYSTALLITE SIZE |
Issue Date: | 2014 |
Publisher: | ROYAL SOC CHEMISTRY |
Abstract: | The current work assesses the impact of structural differences between stable and metastable ZrO2 precursors on the mechanochemical preparation of BaZrO3. Monoclinic (m-ZrO2) and tetragonal (t-ZrO2) zirconia polymorphs were prepared without stabilizing additives by slow alkaline precipitation. High-energy milling of the individual ZrO2 precursors induced different partial transformations in each case. The as-synthesized m-ZrO2 powders showed partial conversion to the tetragonal polymorph on mechanical activation, reaching about 10% t-ZrO2 after 420 min accompanied by increases in strain. In contrast, the as synthesized t-ZrO2 powders underwent the inverse transformation to the monoclinic phase, producing about 50% m-ZrO2 after 120 min with the liberation of strain. The t-ZrO2 precursor was shown to exhibit the higher reactivity with barium peroxide, yielding significantly earlier formation of barium zirconate under room-temperature mechanosynthesis. The progress of the mechanochemical formation of BaZrO3 has been discussed with respect to the differing behaviour of the ZrO2 precursors upon mechanical activation and associated thermodynamic perspectives. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/20551 |
DOI: | 10.1039/c4dt00683f |
ISSN: | 1477-9226 |
Publisher Version: | 10.1039/c4dt00683f |
Appears in Collections: | CICECO - Artigos |
Files in This Item:
File | Description | Size | Format | |
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Enhanced BaZrO3 mechanosynthesis by the use of metastable ZrO2 precursors_10.1039c4dt00683f.pdf | 1.07 MB | Adobe PDF |
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