Formation of BaTiO₃ and PbTiO₃ thin films under mild hydrothermal conditions

Well-crystallized polycrystalline thin films of cubic barium titanate (BaTiO₃) have been synthesized on Ti-covered Si substrates by exposing the substrates to a Ba(OH)₂ aqueous solution at 160 °C and a low pressure less than 1 MPa. It was presumed that the film formation of BaTiO₃ involved a dissolution-crystallization mechanism, which provides an attractive approach to produce other titanate films and powders. Also, we have used for the first time this hydrothermal technique to deposit epitaxial (001)-textured PbTiO₃ thin films on SrTiO₃(100) substrates.