Synthesis of BaTiO3 particles with tailored size by precipitation from aqueous solutions

Well-defined and stoichiometric spherical particles of BaTiO3 of narrow size distribution were produced at 82degrees and 92degreesC by precipitation from chloride solutions in a strong alkaline environment. The size of the particles can be tailored in the range from approximate to10(3) to 70-80 nm by increasing the barium concentration from approximate to0.07 to 0.7 mol/L. The particles are composed of tight aggregates resulting from the assembly of several nanocrystals. The size of the nanocrystals decreases from 200-300 to 30-40 nm by increasing reactant concentration. At low barium concentration (less than or equal to0.07 mol/L at 82degreesC, less than or equal to0.06 mol/L at 92degreesC), formation of BaTiO3 is strongly slowed down and nonstoichiometric, Ti-rich powders are produced. Under these conditions, the particles have the tendency to develop a dendritic-like morphology.