Method of preparing ceramic powders

摘要

A method of forming composition-modified barium titanate ceramic particulate includes mixing a plurality of precursor materials and a precipitant solution to form an aqueous suspension. The plurality of precursors include barium nitrate, titanium chelate, and a metal or oxometal chelate. The precipitant solution includes tetraalkylammonium hydroxide and tetraalkylammonium oxalate. The method further includes treating the aqueous suspension at a temperature of at least 150° C. and a pressure of at least 200 psi, and separating particulate from the aqueous suspension after treating.

主权项

1. A method for preparing a ceramic powder, the method comprising:
providing a plurality of precursor materials in solution comprises a barium source, a titanium source, and a first metal-containing source, and a second metal-containing source, and a third metal-containing source, wherein the titanium source, the first metal-containing source, the second metal-containing source, the third metal-containing source, or any combination thereof comprises a metal ion or oxometal ion and a chelate; combining the plurality of precursor materials in solution with a precipitant solution including an oxalate compound and tetraalkylammonium hydroxide to cause co-precipitation of hydrated hydroxide-oxalate precipitates in a combined solution, wherein the hydrated hydroxide-oxalate precipitates are partly crystalline; hydrothermally treating the hydrated hydroxide-oxalate precipitates to form a full-crystalline or near full-crystalline powder precipitate; separating the powder precipitate from the combined solution; and calcining the separated powder precipitate to form the ceramic powder including a cubic perovskite composition modified barium titanate having a relative permittivity of at least 18,000.