Growth Mechanism of Shape-Controlled Barium Titanate Nanostructures through Soft Chemical Reaction

Abstract

Morphology-controlled barium titanate (BaTiO3) nanostructures, from single-crystal nanorods to nanoparticles, were synthesized by tuning the reaction time of a soft chemical process. Based on the morphology change of the nanostructures, the growth mechanism of the shape-controlled BaTiO3 nanostructures by the soft chemical reaction method was suggested. With the reaction time of 42 h, single-crystal BaTiO3 nanorods with flat surface of facets and defined crystal axis were obtained. As the reaction time was extended to 50 h, a certain volume of nanorods converted to nanoparticles generated by a redissolution−growth reaction. When the reaction time was further elongated to 72 h, the volume of nanoparticles in the product notably increased with single grains of particles that have diameters up to ∼200 nm. It was determined that an ion exchange and the structural transformation from the layer structure of the precursor into the perovskite structure prevailed at an early stage of the soft chemical reaction, and then the nanorods changed to nanoparticles due to the redissolution−growth reaction for reaction times over 42 h.