Preparation of Barium Titanate Nanoparticles by Particle Growth Control

2010 ◽  
Vol 445 ◽  
pp. 171-174 ◽  
Author(s):  
Shuhei Kondo ◽  
Tatsuya Kita ◽  
Petr Pulpan ◽  
Chikako Moriyoshi ◽  
Yoshihiro Kuroiwa ◽  
...  
Keyword(s):  
Growth Rate ◽  
Barium Titanate ◽  
Layer Thickness ◽  
Growth Control ◽  
Particle Growth ◽  
Particle Structure ◽  
Barium Titanyl Oxalate ◽  
Jet Milling ◽  
Titanyl Oxalate ◽  
Batio3 Nanoparticles

Barium titanate (BaTiO3) nanoparticles were prepared by a two-step thermal　decomposition method using barium titanyl oxalate nanoparticles of size 30 nm with and without dry-jet milling. Dry-jet milled barium titanyl oxalate nanoparticles (BTO-B) were well-dispersed whereas those without the dry-jet milling procedure (BTO-A) were partially aggregated. A heat annealing of obtained BaTiO3 nanoparticles at the same temperature resulted in crystallite sizes of the BTO-A derived BaTiO3 nanoparticles much smaller than those of the BTO-B derived. A mesoscopic particle structure analysis of revealed much thinner surface cubic layer thickness of the BTO-B derived BaTiO3 nanoparticles compared with the BTO-A derived BaTiO3 nanoparticles. This indicated the particle growth rate to be the most important parameter for the surface cubic layer thickness determination. A relationship between the surface cubic layer thickness and the particle growth rate was investigated precisely in this study.

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

2009 ◽  
Vol 421-422 ◽  
pp. 506-509 ◽  
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.

Size Dependence of Dielectric Properties for Barium Titanate Nanoparticles Prepared under Various Vacuum Atmospheres

2006 ◽  
Vol 320 ◽  
pp. 139-142 ◽  
Author(s):  
Satoshi Wada ◽  
Masanori Ohishi ◽  
Kayo Takizawa ◽  
Takuya Hoshina ◽  
Hirofumi Kakemoto ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Barium Titanate ◽  
Fine Particles ◽  
Particle Growth ◽  
Dielectric Measurement ◽  
High Particle ◽  
Heat Treated ◽  
Barium Titanyl Oxalate ◽  
Barium Titanate Nanoparticles ◽  
Batio3 Nanoparticles

Barium titanate (BaTiO3) fine particles were prepared using the 3-step thermal decomposition method of barium titanyl oxalate under various vacuum atmospheres. In this method, the first two steps prepared BaTiO3 nanoparticles with 30 nm, and at the 3rd step, BaTiO3 nanoparticles were heat-treated at various temperature and degree of vacuum. As a result, as degree of vacuum is high, particle size of BaTiO3 fine particles decreased. Moreover, the dielectric constant of BaTiO3 fine particles was measured using the powder dielectric measurement method with slurry. The dielectric constant of these particles showed the dielectric maximum of 4,320 at 200 nm despite degree of vacuum. This result revealed that degree of vacuum during particle growth of BaTiO3 particles had no relation about dielectric constant.

Development of New Preparation Method for nm-Sized Barium Titanate Particles

2006 ◽  
Vol 301 ◽  
pp. 215-218 ◽  
Author(s):  
Michiyasu Nishiyama ◽  
Takuya Hoshina ◽  
Hirofumi Kakemoto ◽  
Takaaki Tsurumi ◽  
Satoshi Wada
Keyword(s):  
Barium Titanate ◽  
Precursor Solution ◽  
Average Diameter ◽  
Solution Concentration ◽  
Decomposition Temperature ◽  
Barium Titanyl Oxalate ◽  
Two Parameters ◽  
20 Nm ◽  
Wide Size Distribution ◽  
Titanyl Oxalate

A new method for ultrafine barium titanate (BaTiO3) particles with diameters of around 5 nm is proposed. In this method, barium titanyl oxalate aqua solution with low concentration below 10-3 mol/l was used as the starting material. The droplets with a size below 3 μm were atomized with an ultrasonic vibrator, dried and thermally decomposed at higher temperatures over 300°C. In the preparation of the BaTiO3 particles, there were two parameters such as thermal decomposition temperature and precursor solution concentration. Therefore, various particles were prepared by changing these parameters. Finally, non-aggregated nm-sized BaTiO3 particles with an average diameter of 5.2 nm, despite wide size distribution from 2 to 20 nm, were prepared by using the precursor solution with 10-6 mol/l.

Preparation of Barium Titanate Nanocube Particles by Solvothermal Method and their Characterization

2008 ◽  
Vol 388 ◽  
pp. 111-114 ◽  
Author(s):  
Satoshi Wada ◽  
Aki Nozawa ◽  
Masaru Ohno ◽  
Takaaki Tsurumi ◽  
Yoshihiro Kuroiwa
Keyword(s):  
Barium Titanate ◽  
Organic Solvent ◽  
Solvothermal Method ◽  
Particle Growth ◽  
Inorganic Materials ◽  
20 Nm ◽  
Batio3 Nanoparticles ◽  
Selection Of

Barium titanate (BaTiO3) nanocube particles below 20 nm were prepared by solvothermal method. To prepare nanocubes, a selection of organic solvent and inorganic materials of Ba and Ti sourses was most important. At the temperatures above 200 °C, a nucleation and particle growth of BaTiO3 nanoparticles led to a formation of the BaTiO3 nanocubes with a size of 10-15 nm.

Preparation and Characterization of Highly-Dispersed and Highly-Crystalline Barium Titanate Nanoparticles

2013 ◽  
Vol 566 ◽  
pp. 273-276
Author(s):  
Tatsuya Kita ◽  
Takahiro Takei ◽  
Nobuhiro Kumada ◽  
Kouichi Nakashima ◽  
Ichiro Fujii ◽  
...  
Keyword(s):  
Barium Titanate ◽  
X Ray Diffraction ◽  
Reduced Pressure ◽  
Barium Titanyl Oxalate ◽  
Highly Dispersed ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Barium Titanate Nanoparticles ◽  
Titanyl Oxalate

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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