Hydrothermal Soft Chemical Synthesis and Particle Morphology Control of BaTiO 3 in Surfactant Solutions

Barium titanate (BaTiO 3 ) particles with book‐like and spherical morphology were prepared by using a hydrothermal soft chemical process in the presence of a cationic surfactant. A layered titanate of H 1.07 Ti 1.73 O 4 with a lepidocrocite‐like structure and plate‐like particle morphology was used as the precursor. The layered titanate was hydrothermally treated in a Ba(OH) 2 –(HTMA‐OH) ( n ‐hexadecyltrimethylammonium hydroxide) solution or a Ba(OH) 2 –(HTMA‐Br) ( n ‐hexadecyltrimethylammonium bromide) solution in a temperature range of 80°–250°C to prepare BaTiO 3 . The intercalation reaction of HTMA + with the layered titanate promotes the structural transformation reaction from the layered titanates to BaTiO 3 , while it inhibits the structural transformation reaction to anatase under the hydrothermal conditions. The particle morphology of BaTiO 3 prepared by this method dramatically changes with changing reaction conditions. HTMA + plays an important role in changing particle morphology in the hydrothermal soft chemical process.