Synthesis of High Aspect Ratio PbBi4Ti4O15 and Topochemical Conversion to PbTiO3-Based Microplatelets

Perovskite microplatelets of the composition 0.4(Na1/2Bi1/2) TiO3–0.6PbTiO3 (0.4NBT–0.6PT) were synthesized by topochemical conversion of the Aurivillius phase PbBi4Ti4O15 in a NaCl/Bi2O3/PbO flux system. To facilitate morphologic control, we investigate the effects of TiO2 particle size on molten s...

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Bibliographic Details
Published in:Journal of the American Ceramic Society 2011-08, Vol.94 (8), p.2323-2329
Main Authors: Poterala, Stephen F., Meyer, Jr, Richard J., Messing, Gary L.
Format: Article
Language:English
Subjects:
Ceramics
Conversion
Density
Free energy
Fused salts
Nucleation
Perovskites
Titanium dioxide
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Summary:Perovskite microplatelets of the composition 0.4(Na1/2Bi1/2) TiO3–0.6PbTiO3 (0.4NBT–0.6PT) were synthesized by topochemical conversion of the Aurivillius phase PbBi4Ti4O15 in a NaCl/Bi2O3/PbO flux system. To facilitate morphologic control, we investigate the effects of TiO2 particle size on molten salt growth of the PbBi4Ti4O15 phase. We find that the initial nucleation density and [100] thickness of this phase are controlled by the TiO2 dissolution rate, while the platelet diameter is determined by Ostwald ripening. PbBi4Ti4O15 microplatelets produced using these methods can be converted entirely to a tetragonal perovskite phase (c/a=1.051) while retaining the dimensions of the precursor PbBi4Ti4O15 phase. We propose that the resulting 0.4NBT–0.6PT composition is favored thermodynamically due to the lower free energy of this composition relative to pure PbTiO3. In addition, partial (Na1/2Bi1/2)TiO3 substitution is kinetically favored as it reduces A‐site diffusion during the topochemical conversion process.
ISSN:0002-7820
1551-2916
DOI:10.1111/j.1551-2916.2010.04369.x