Synthesis and sintering of nanocrystalline barium titanate powder under nonisothermal conditions. II. Phase analysis of the decomposition products of barium titanyl-oxalate and the synthesis of barium titanate

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.

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Synthesis of Barium Titanate Nanoparticles from Decomposition of Barium Titanyl Oxalate Tetrahydrate with Aid of Supercritical Water

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.463-464.781 ◽

2012 ◽

Vol 463-464 ◽

pp. 781-787

Author(s):

Jin Tao Huang ◽

Tomoya Imura ◽

Norimasa Sakamoto

Keyword(s):

Supercritical Water ◽

Critical Conditions ◽

High Quality ◽

Barium Titanyl Oxalate ◽

Alkaline Conditions ◽

Barium Titanate Nanoparticles ◽

First Time ◽

Titanyl Oxalate ◽

Synthesis Of Barium Titanate ◽

Better Than

A novel process of BaTiO3 manufacture was conducted by using supercritical water. Preparation of BaTiO3 nanoparticles was investigated from decomposition of BaTiO(C2O4)2•4H2O (BTOT) with aid of supercritical water for the first time. When BTOT was exposed to supercritical water around 673 K and 30 MPa, it decomposed quickly in 5-22 seconds. The products formed strongly reply on environmental conditions. BaCO3 and TiO2 were always observed as the products in the absence of alkaline additives. BaTiO3 nanoparticles with specific surface area as high as 12~14 m2/g were able to be obtained under strong alkaline conditions, such as NaOH/COSubscript text2=2/1. It was found that environment of supercritical water was better than sub-critical conditions to obtain high quality BaTiO3 particles with fewer defects. Employment of supercritical water significantly reduced the reaction time and temperature compared to other BaTiO3 manufacture processes utilizing BTOT as precursor.

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Properties of barium titanate powders in relation to the heat treatment of the barium titanyl oxalate precursor

Inorganic Materials ◽

10.1134/s0020168512060167 ◽

2012 ◽

Vol 48 (6) ◽

pp. 613-618 ◽

Cited By ~ 5

Author(s):

V. N. Shut ◽

S. V. Kostomarov

Keyword(s):

Heat Treatment ◽

Barium Titanate ◽

Oxalate Precursor ◽

Barium Titanyl Oxalate ◽

Titanyl Oxalate

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Preparation of Barium Titanate Nanoparticles by Particle Growth Control

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.445.171 ◽

2010 ◽

Vol 445 ◽

pp. 171-174 ◽

Cited By ~ 1

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.

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