TY - JOUR
T1 - Preparation of monodispersed spherical barium titanate particles
AU - Chen, Kun Yuan
AU - Chen, Yu Wen
N1 - Funding Information:
This research was supported by the National Science Council of the Republic of China.
PY - 2005/2
Y1 - 2005/2
N2 - Spherical barium titanate particles with cubic phase were synthesized by a low-temperature hydrothermal reaction. Firstly, The method of hydrolysis of titanium tetrachloride was used for producing spherical TiO 2 particles (0.45-1.5 μ m) with various concentrations of TiCl 4(0.05-0.2 M) and volume ratios of acetone to water solutions (RH = 0-4). These TiO 2 particles were converted to barium titanate by a hydrothermal conversion in a barium hydroxide solution. The size and morphology of the TiO 2 particles was controlled by the volume ratio of acetone to water (RH ratio) in the mixed solvent. At the RH ratio of 3, the morphology of TiO 2 particles was very uniform and discrete. These TiO 2 particles were in the anatase phase and were converted to the rutile phase when the calcination temperature increased to 700°C and above. Uniform and spherical barium titanate particles were successfully synthesized from the as-prepared TiO 2 particles by using a hydrothermal reaction in a barium hydroxide solution. The Ba/Ti ratios, reaction temperature, and reaction time did not influence the size and morphology of BaTiO 3 particles, but increased the concentration of unfavorable salts such as Ba(OH) 2 and BaCO 3. The high purity BaTiO 3 particles could be obtained by washing with formic acid to remove the unfavorable salts. The size and morphology of the BaTiO 3 particles remained the same as those of the TiO 2 particles, confirming the in-situ transformation mechanism for the conversion of TiO 2 to BaTiO 3. The as-synthesized particles were cubic phase and transformed to tetragonal phase after calcinations at 1150°C 1 h. The mean density of the pellets sintered at 1300° C for 2 h was 5.86 g/cm 3 and accounted for 97.34% of the theoretical density.
AB - Spherical barium titanate particles with cubic phase were synthesized by a low-temperature hydrothermal reaction. Firstly, The method of hydrolysis of titanium tetrachloride was used for producing spherical TiO 2 particles (0.45-1.5 μ m) with various concentrations of TiCl 4(0.05-0.2 M) and volume ratios of acetone to water solutions (RH = 0-4). These TiO 2 particles were converted to barium titanate by a hydrothermal conversion in a barium hydroxide solution. The size and morphology of the TiO 2 particles was controlled by the volume ratio of acetone to water (RH ratio) in the mixed solvent. At the RH ratio of 3, the morphology of TiO 2 particles was very uniform and discrete. These TiO 2 particles were in the anatase phase and were converted to the rutile phase when the calcination temperature increased to 700°C and above. Uniform and spherical barium titanate particles were successfully synthesized from the as-prepared TiO 2 particles by using a hydrothermal reaction in a barium hydroxide solution. The Ba/Ti ratios, reaction temperature, and reaction time did not influence the size and morphology of BaTiO 3 particles, but increased the concentration of unfavorable salts such as Ba(OH) 2 and BaCO 3. The high purity BaTiO 3 particles could be obtained by washing with formic acid to remove the unfavorable salts. The size and morphology of the BaTiO 3 particles remained the same as those of the TiO 2 particles, confirming the in-situ transformation mechanism for the conversion of TiO 2 to BaTiO 3. The as-synthesized particles were cubic phase and transformed to tetragonal phase after calcinations at 1150°C 1 h. The mean density of the pellets sintered at 1300° C for 2 h was 5.86 g/cm 3 and accounted for 97.34% of the theoretical density.
UR - http://www.scopus.com/inward/record.url?scp=16244409536&partnerID=8YFLogxK
U2 - 10.1007/s10853-005-6518-z
DO - 10.1007/s10853-005-6518-z
M3 - 期刊論文
AN - SCOPUS:16244409536
SN - 0022-2461
VL - 40
SP - 991
EP - 998
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 4
ER -