Crystalline LaAlO3 nanoparticles were synthesized at relative low temperatures, using a citrate-precursor technique. La(NO3)3, Al(NO3)3, and C3H4(OH)(COOH)3, in a molar ratio of 1:1:1, were dissolved in deionized water. NH4OH was used to adjust the aqueous solution to pH 7. After drying, the citrate precursors were charred at 350 °C, followed by calcination at different temperatures, in air or oxygen atmosphere. The thermochemical properties of the resultant particles were analyzed using thermogravimetric and differential thermal analysis, X-ray diffractometry, infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Effects of calcination temperature and heating atmosphere on the formation of crystalline LaAlO3 nanoparticles were investigated. In O2 atmosphere, clacining the citrate-derived charred solid precursor at 700 °C for 3 h can decompose all intermediates to produce pure LaAlO3 nanoparticles (particle sizes ≤ 100 nm) with an average crystallite size of about 24 nm and possessing high sinterability.
Journal of Alloys and Compounds 509(5), pp.1984-1988