Structure Analysis of Nanocrystalline MgO Aerogel Prepared by Sol-Gel Method

Abstract:

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Wet gel obtained by sol-gel technique was dried in supercritical CO2 to prepare hydrated form of magnesium oxide. Calcination at 723 K under vacuum yielded nanocrystalline MgO aerogel. Structure studies were performed by X-ray diffraction, scanning and transmission electron microcopies. Electron microscopy images reveal rough, unfolded and ramified structure of solid skeleton. Specific surface area SBET was equal to 238 m2/g. X-ray pattern reveals the broadened diffraction lines of periclase, the only crystalline form of magnesium oxide. The gamma crystallite size distribution was determined using FW 5 4 / 5 1 M method proposed by R. Pielaszek. The obtained values of and σ (measure of polydispersity) of particle size parameters are equal to 6.5 nm and 1.8 nm, respectively, whereas the average crystallite size estimated by Williamson-Hall procedure was equal to 6.0 nm. The obtained at Rietveld refinement Rwp, and S fitting parameters equal to 6.62% and 1.77, respectively, seem to be satisfactory due to the nanosize of MgO crystallites and because of the presence of amorphous phase.

Info:

Periodical:

Solid State Phenomena (Volume 130)

Edited by:

Danuta Stróż & Małgorzata Karolus

Pages:

203-206

DOI:

10.4028/www.scientific.net/SSP.130.203

Citation:

G. Dercz et al., "Structure Analysis of Nanocrystalline MgO Aerogel Prepared by Sol-Gel Method", Solid State Phenomena, Vol. 130, pp. 203-206, 2007

Online since:

December 2007

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$35.00

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