Effects of chelation reactions between metal alkoxide and acetylacetone on the preparation of MgAl2O4 powders by sol-gel process

Magnesium aluminate spinet (MgAl2O4) were synthesized via the sol-gel method, using magnesium aluminum double n-butoxide as precursors. The n-butoxide, prepared by the direct reaction of stoichiometric magnesium, aluminum and adequate n-butanol, was modified by acetylacetone as the chelating agent to control the speed of hydrolysis. Gel samples were identified as the mixture of Mg2Al(OH)(7) and MgAl2(OH)(8) phases, which converted to pure MgAl2O4 spinet phase at 800 degrees C. Then dense spinet ceramics with 96% of relative density were prepared by sintering in air at 1600 degrees C. Besides, the morphology of the powders and sintered ceramics has been investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). (C) 2012 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.