CRYSTALLINE-STRUCTURE OF MGO PREPARED BY THE SOL-GEL TECHNIQUE WITH DIFFERENT HYDROLYSIS CATALYSTS

We have prepared MgO by the sol-gel technique using different hydrolysis catalysts that control the size of the particle and its evolution with temperature. The phases in the sample were identified by X-ray diffraction. The evolution in the temperature range between 150 and 900 degrees C of the MgO crystalline structure was studied by Rietveld refinement technique. As a profile for the diffraction peaks we used a modified pseudo-Voigt function with the average particle size as one of its fitting parameters. This allowed us to follow the evolution of particle size with temperature for the different hydrolysis catalysts. From the Mg deficiency in the MgO lattice we find Mg:O molar ratios between 3.56(2):4.00 and 3.85(3):4.00 depending on the average particle size. (C) 1995 Academic Press, Inc.