Fabrication and characterization of Ca 3Co 4O 9 nanoparticles by sol-gel method

Ca 3Co 4O 9 nanoparticles were fabricated by using calcium nitrate and cobalt nitrate as raw materials and citric acid as complexing agent through a citrate sol-gel method. Polyethylene glycol (PEG) 1000 was added as dispersing agent with different mass ratios. Pyrolytic decomposition of the dried gel and generative process of Ca 3Co 4O 9 were investigated by TG-DSC, XRD. The microstructures of the particles were characterized by SEM and TEM. Ca 3Co 4O 9 particles contained plate-shaped grains with layered structure. No second phases were found in the samples which were heated in the calcined temperature range of 750 - 900 °C for 4 h in air. The average size of the Ca 3Co 4O 9 particles prepared with 3% PEG 1000 calcined at 800 °C for 4 h is 30 - 70 nm. © The Nonferrous Metals Society of China and Springer-Verlag Berlin Heidelberg 2011.