Synthesis of strontium titanate nanoparticles in an emulsion stabilized bymechanical stirring: control of grain size

An original synthesis for obtaining nanoparticles of SrTiO3 with controlled grain size has been developed. It proceeds by a nucleation/growth mechanis m in a pre-stabilized water/alcohol emulsion obtained by continuous stirrin g. The key parameters of the synthesis are the concentration of precursors and the size of the droplets which has been varied by adjusting the water/a lcohol volume-ratio. The change in morphology of the so-obtained powders, c haracterized by XRD, nitrogen adsorption and TEM experiments, has been expl ained based on the assumptions that the number of nuclei is proportional to the surface area water/alcohol interface and that the nucleation rate is p roportional to the precursor concentration. (C) 1999 Academie des sciences/ Editions scientifiques et medicales Elsevier SAS.