Preparation of barium strontium titanate powder from citrate precursor

Abstract

TiCl4 or titanium isopropoxide reacted with citric acid to form a titanyl citrate precipitate. Barium strontium citrate solutions were then added to the titanyl citrate reaction to form gels. These gels were dried and calcined to (Ba,Sr)TiO3 powders. The gels and powders were characterized by DSC/TGA, IR, SEM and XRD analyses. These results showed that, at 500 °C, the gels decomposed to Ba,Sr carbonate and TiO2, followed by the formation of (Ba,Sr)TiO3. The onset of perovskite formation occurred at 600 °C, and was nearly complete at 1000 °C. Traces of SrCO3 were still present. The cation ratios of the titanate powder prepared in the pH range 5–6 were closest to the original stoichiometry. Only 0.1 mol% of the free cations remained in solution. The titanyl citrates were precipitated in either ethanol or acetone. The acetone‐derived precipitates were always viscous, but those with a sufficient quantity of alcohol were powdery. The specific surface areas of the ceramic powders obtained by air‐ , vacuum‐ and freeze‐drying methods were 8.3 × 103, 10.2 × 103 and 12.5 × 103m2 kg−1, respectively. The powder obtained by freeze‐drying had the lowest degree of agglomeration. The precipitated powders of titanyl citrate which were freeze‐dried and calcined at 1100 °C were compacted and sintered at 1300 °C to obtain dense ceramic bodies with 95% of the theoretical density. Copyright © 1999 John Wiley & Sons, Ltd.

Template‐Free Synthesis of Hollow Porous Strontium Titanate Particles

“…In the precursor solution, citric acid and acetic acid chelated Sr and Ti cations, and then formed carbonate complexes of Sr 2 Ti 2 O 5 CO 3 . Consequently, after atomization and heating, the Sr 2 Ti 2 O 5 CO 3 complexes in droplets decomposed into SrCO 3 and TiO 2 . As the temperature increased, SrCO 3 and TiO 2 formed the final SrTiO 3 particles.…”

Synthesis and Characterization of Fe and Ni Co-Doped Ba0.6Sr0.4Tio3Prepared by Sol-Gel Technique

“…Hence, the result shows that BST nanopowder obtained at 850°C are more pure than BSTF and BSTN at the same temperature. Furthermore, the absorption band at 611 cm -1 is assigned to specific vibrations of Ti-O bonds for pure BST [21]. Also, a shoulder around 954 cm -1 and a dip at 1063 cm-1 appears to be getting more prominent in Fe and Ni doped BST samples corresponding to the formation of new bonds due to dopant Fe and Ni.…”

Synthesis of Barium Titanate Piezoelectric Ceramics for Multilayer Actuators (MLAs)

“…BaTiO3 is destined for many applications in different industries, such as energy storage devices and multilayer actuators (MLAs) (Miot et al, 1995;Kao and Yang, 1999). These applications require materials with a good density, a high dielectric constant and a low loss factor.…”

“…However, this procedure results in agglomeration, poor chemical homogeneity and formation of secondary phases which harm the electrical properties of BaTiO3 (Kim et al, 2009, Othman et al, 2014. However, the solid state method has the advantages of low production cost, precise stoichiometry control, operating simplicity and possibility of its application on mass production (Kao and Yang, 1999;Kholodkova et al, 2012).…”