Crystalline barium titanate synthesized in sub- and supercritical water

• Published in: The Journal of supercritical fluids 2016-11, Vol.117, p.194-202
• Main Authors: Kholodkova, Anastasia A., Danchevskaya, Marina N., Ivakin, Yurii D., Muravieva, Galina P., Tyablikov, Alexander S.
• Format: Article
• Language: English
• Subjects: Barium titanate; Crystal growth; Hydrothermal synthesis; Supercritical water; Water vapor
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2016.06.018

[Display omitted] •Crystals BaTiO3 in tetragonal modification were synthesized in water media (liquid, gaseous, supercritical).•Synthesis in gaseous and supercritical water yielded BaTiO3 particles with narrow size distribution.•The use of supercritical water as reaction medium leads to low amount of volatile admixtures in produced BaTiO3.•BaTiO3 powder produced in gaseous and supercritical water performed higher sinterability than the hydrothermally derived BaTiO3.•Supercritical water is the most appropriate water medium for the synthesis of BaTiO3 as raw material for ceramics. The promoting effect of water in different states of aggregation on the transformation processes in oxide mixture was studied in case of BaTiO3 formation. The reaction between barium and titanium oxide was carried out in liquid, in gaseous and in supercritical water. The state of aggregation of the reaction medium had an influence on the degree of transformation of the reagents and on the characteristics of produced BaTiO3 such as the crystal size, the content of volatile impurities and sinterability. On the basis of comparative investigation it was concluded that the synthesis in supercritical water appeared to be the most effective way for production of pure fine-crystalline BaTiO3 for the ceramics preparation.