Crystallization kinetics of lanthanum monoaluminate (LaAlO3) nanopowders prepared by co-precipitation process

Lanthanum monoaluminate (LaAlO3) nanopowders were synthesized using La(NO3)(3)center dot 6H(2)O and Al(NO3)(3)center dot 6H(2)O as starting materials by a co-precipitation method. The crystallization kinetics of the LaAlO3 nanopowders has been investigated by using differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The XRD results and SAED patterns show that the rhombohedral LaAlO3 nanopowders have been obtained when the precipitates as calcined at 1092 K for 10 min. The activation energy for the crystallization of the rhombohedral LaAlO3 nanopowders is determined as 286.75 kJ/mol by a non-isothermal method. The TEM examination shows that the rhombohedral LaAlO3 has a spherical morphology with the size ranging from 30 to 50 nm. (C) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.