Controlled double-jet precipitation of uniform colloidal crystalline particles of Zr- and Sr-doped barium titanates

The synthesis of uniform colloidal crystalline particles of Zr- and Sr-doped barium titanates at a low temperature of 85 degrees C by the controlled double-jet precipitation (CDJP) technique is described. The stoichiometry of the powders can be precisely controlled by adjusting the compositions of the starting reactant solutions. Barium titanate with 20% Zr substitution, sintered at 1275 degrees C, satisfied the requirements for the Y5V multilayer capacitors application. The grain sizes are uniform and small, ranging from 1 to 3 mu m. Solids with an extremely sharp change in the dielectric constant as a function of temperature, which are suitable for thermal IR detectors application, can be obtained when both Sr and Zr are incorporated as dopants.