Preparation of Highly Dispersed Barium Titanate Nanoparticles from Barium Titanyl Oxalate Nanoparticles and Their Dielectric Properties

Highly dispersed barium titanate (BaTiO3, BT) nanoparticles were prepared by the new 2-step thermal decomposition method of barium titanyl oxalate of 30 nm in size. The nanoparticles were heated at 450 °C for 5 hours in air to yield intermediate product: Ba2Ti2O5CO3. Highly dispersed BaTiO3 nanoparticles were prepared by rotationally stirring it at the reduced pressure of 0.2 Pa at various temperatures between 800 °C and 900 °C. The particle size and morphology of the BaTiO3 nanoparticles were investigated by X-ray diffraction and scanning electron microscopy. These measurements showed that the BT nanoparticles were highly dispersed and well-crystallized.

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Preparation of nm-ordered barium titanate fine particles using the 2-step thermal decomposition of barium titanyl oxalate and their dielectric properties

Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002. ◽

10.1109/isaf.2002.1195920 ◽

2003 ◽

Author(s):

S. Wada ◽

T. Hoshina ◽

H. Kakemoto ◽

T. Tsurumi

Keyword(s):

Thermal Decomposition ◽

Dielectric Properties ◽

Barium Titanate ◽

Fine Particles ◽

Barium Titanyl Oxalate ◽

Titanyl Oxalate

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Particle Structure Analysis of Highly-Dispersed Barium Titanate Nanoparticles Obtained from Barium Titanyl Oxalate Nanoparticles and their Dielectric Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.421-422.506 ◽

2009 ◽

Vol 421-422 ◽

pp. 506-509 ◽

Cited By ~ 5

Author(s):

Shuhei Kondo ◽

Chikako Moriyoshi ◽

Yoshihiro Kuroiwa ◽

Satoshi Wada

Keyword(s):

Dielectric Constant ◽

Barium Titanate ◽

Layer Thickness ◽

Rietveld Analysis ◽

Particle Structure ◽

Maximum Dielectric Constant ◽

Barium Titanyl Oxalate ◽

Barium Titanate Nanoparticles ◽

Titanyl Oxalate ◽

Batio3 Nanoparticles

Barium titanate (BaTiO3) nanoparticles were prepared by two-step thermal decomposition method of barium titanyl oxalate nanoparticles with a size of 30 nm. The BaTiO3 particle sizes were changed from 12.3 to 142 nm by control of temperature at 2nd step. The X-ray diffraction (XRD) measurement revealed that a clear splitting of 002 and 200 planes was observed over 40 nm, and the c/a ratio of 1.0089 was obtained for the BaTiO3 nanoparticles with a size of 62.3 nm. This high c/a ratio in the BaTiO3 nanoparticles suggested that its mesoscopic particle structure was composed of very thin surface cubic layer below 5 nm. Thus, synchrotron XRD data were analyzed using a “two layers” model and a “three layers” model. The Rietveld analysis using the three layers model resulted in the particle structure with a cubic layer thickness of 2.5 nm and structure gradient layer thickness of 7.5 nm. Finally, the dielectric constant of these BaTiO3 nanoparticles with thin surface cubic layer was measured at room temperature, and the maximum dielectric constant over 30,000 was obtained at the nanoparticles with a size of 83.6 nm.

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