Synthesis and characterization of nanoparticles of Ba2EuHfO5.5: a new complex perovskite ceramic oxide

Ba2EuHfO5.(5,) a complex perovskite oxide, has been synthesized as nanopart icles using a modified self-propagating combustion method for the first tim e. The Ba, Eu and Hf ions required for the formation of Ba2EuHfO5.5 were ob tained in solution by dissolving a stoichiometric mixture of BaCO3, Eu2O3 a nd HfO2 heated at 1200 degreesC for 4 h in boiling nitric acid. By complexi ng the ions with citric acid and using ammonia as fuel, it was possible to get Ba2EuHfO5.5 as nanoparticles in a single step combustion process. The s olid combustion product was characterized using X-ray powder diffraction, t hermogravimetric analysis, differential thermal analysis, infrared spectros copy, surface area analysis and high resolution transmission electron micro scopy. The high resolution transmission electron microscopic examination of the product showed an average particle size of about 25 nm with a standard deviation of 13 nm. The nanoparticles of Ba2EuHfO5.5 synthesized by the co mbustion technique could be sintered to > 97% of the theoretical density at a relatively low temperature. (C) 2001 Elsevier Science B.V. All rights re served.