Preparation of barium hafnate fine powders by oxalate method

Barium hafnate (BaHfO3) precursor was prepared by mixed barium nitrate and hafnium (IV) chloride with ammonium oxalate aqueous solution. Barium hafnate powders were obtained by decomposition of the precipitate precursor at 800 °C for 2 h. As a dispersant, polyethylene glycol (PEG6000) was used in the precipitation reaction and the influence of dispersant dosage on particle size was studied. X-ray diffraction analysis (XRD) showed the powders was pure cubic BaHfO3 without impurities. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that the size distribution was uniform, and the average grain size was about 50 nm.