Synthesis and characterization of BaTiO3 nanoparticles in oxygen atmosphere

A new synthesis route to obtain high-purity barium titanate, BaTiO3, using the sol–gel-hydrothermal reaction of TiCl4 and a BaCl2 solution in an oxygen atmosphere has been developed. The synthesized BaTiO3 nanoparticles are nearly spherical. Their grain sizes are determined by the reaction temperature, reaching values as low as 50 nm when the particles are synthesized at 200 °C; interestingly even those particles with the smallest grain sizes displayed a ferroelectric behavior as characterized by a polarization hysteresis loop. The microstructure and composition of the as-synthesized samples were investigated by X-ray diffraction (XRD), high-resolution TEM (HRTEM), Raman spectroscopy, atomic force microscopy (AFM) and energy-dispersive X-ray spectroscopy (EDS).