Preparation of spherical nanoparticles of LaAlO3 via the reverse microemulsion process

Spherical LaAlO3 nanoparticles in a reverse microemulsion consisting of solution (water phase), Tween-80 and Span-80 (surfactant), n-butanol (cosurfactant, and cyclohexane (oil phase) were prepared. Precursor powders and calcined powders were characterized by differential thermal analysis (DTA), thermogravimetry analysis (TG), X-ray diffraction (XRD) and transmission electron microscopy (TEM). A pure perovskite LaAlO3 formed when the precursor hydroxides calcined at 800 degrees C for 2 h. The particle size was about 50 nm and the shape of the monodisperse particles is spherical. The reverse microemulsion process can dramatically lower the crystallization temperature of LaAlO3 about 700 degrees C than the classical solid-state reaction method. (C) 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved.