Fabrication of lead titanate nanocrystals via gas-bubbling sol–gel process

With Pb(CH₃COO)₂ · 3H₂O and Ti(C₄H₉O)₄ as precursor materials, (CH₃)₂CHOH and ammonium tartrate as solvent and surfactant, respectively, the ferroelectric lead titanate (PT) nanocrystals of tailorable sizes were successfully prepared via a novel gas-bubbling sol–gel process, in which water and ammonia were carried into the solution by nitrogen gas through a bundle of stainless steel needle-like tubes, and a subsequent heating treatment in an oxygen-free atmosphere. It has been found that the dimensions of resulting nanocrystals are strongly affected by the internal diameter of tubes for gas-bubbling, while the velocity of carrier gas flowing in the tubes mainly controls the bubbling rate or the yield of nanocrystals. The possible mechanism for the formation of size-tailorable nanocrystals via such a gas-bubling sol–gel process is discussed in this paper.