Characterization of BaZrO ₃ nanoparticles prepared by reverse micelle synthesis

Nanoparticles of BaZrO ₃ have been prepared through a reverse micelle synthesis. The as-processed particles consisted of amorphous Ba-Zr-O and crystalline Zr _0.95O ₂ particles with an average diameter of approximately 7.5 nm. Conversion of the powders to crystalline BaZrO ₃ nanoparticles occurred upon heat treatment at 700°C in air for 0.5 h. The heat-treated powder consisted primarily of BaZrO ₃ and a small quantity of ZrO ₂, with an average particle size increase to 17.3 nm. The as-processed and heat treated nanoparticles were analyzed by both X-ray diffraction and transmission electron microscopy. The nanocrystalline BaZrO ₃ particles were characterized as having a faceted octahedral shape with {100} and {111} surfaces. A brief evaluation of the stability of these surfaces is also discussed.