Synthesis and thermodynamic stability of multiferroic BiFeO3
| Autor: | Pedro B. Tavares, T.T. Carvalho |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Materials science
Rietveld refinement Mechanical Engineering Analytical chemistry Mineralogy Thermal treatment Condensed Matter Physics Mechanics of Materials visual_art Phase (matter) visual_art.visual_art_medium General Materials Science Chemical stability Ceramic Particle size Perovskite (structure) Sol-gel |
| Zdroj: | Materials Letters. 62:3984-3986 |
| ISSN: | 0167-577X |
| DOI: | 10.1016/j.matlet.2008.05.051 |
| Popis: | Ceramic BiFeO 3 samples were prepared by the sol gel combustion method using urea as fuel. The obtain powders were thermal treated at different temperatures (300–840 °C) and times (1–64 h) to investigate the best synthesis conditions of the material. The resulting materials were analysed by TGA, FTIR, SEM/EDS and XRD. Rietveld analysis was applied to the diffraction data. The temperature and time of the heat treatment are critical for a high BiFeO 3 phase content. Thermal treatment of 1 h at 600 °C yielded 99% molar of the BiFeO 3 phase with a mean particle size of 120 nm. Upper or lower calcinations temperatures yielded higher content of the secondary phases Bi 2 Fe 4 O 9 and Bi 25 FeO 39 . Further heat treatment in air or in argon, up to 64 h, induces a decomposition of the BiFeO 3 phase according to the reaction 49 BiFeO 3 BiFeO 3 → 12 Bi 2 Fe 4 O 9 + Bi 25 FeO 39 pointing out that BiFeO 3 is not thermodynamically stable at 600 °C. The BiFeO 3 decomposition follows Avrami–Erofeev law with a slope of 1 indicating a one-dimensional kinetics. |
| Databáze: | OpenAIRE |
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