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

Well-defined and stoichiometric spherical particles of BaTiO,
of narrow size distribution were produced at 82° and 92°C by
precipitation from chloride solutions in a strong alkaline
environment. The size of the particles can be tailored in the
range from ~10(3) to 70-80 nm by increasing the barium
Concentration from ~0.07 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 (<=0.07 mol/L at 82°C,
<=0.06 mol/L at 92°C), 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.