Preparation of Spherical Bi3.25La0.75Ti3O12 Nanocrystals by a Sol-Gel Inverse Mini-Emulsion Approach

Monodisperse and spherical lanthanum bismuth titanate (Bi3.25La0.75Ti3O12, BLT) nanocrystals with an average size of similar to 60 nm were synthesized by in situ crystallization of spherical gel particles (similar to 120 nm in diameter) at elevated temperatures in a carbonate environment. The gel particles were obtained by a sol-gel inverse mini-emulsion manipulation and a gelation process at 60 degrees C. X-ray diffraction technique and Raman spectrum measurement were used to trace the formation of crystalline phases in the gel particles during heat treatment, and single-phase BLT nanocrystals were obtained after firing at 500 degrees C for 4 h. The morphology and size of the gel particles and BLT nanocrystals were characterized by field-emission scanning electron microscopy and transmission electron microscopy. The possible mechanism underlying the formation of spherical BLT nanocrystals through a,sol-gel inverse mini-emulsion approach was discussed.