In:
Solid State Phenomena, Trans Tech Publications, Ltd., Vol. 130 ( 2007-12), p. 203-206
Abstract:
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 〈 R 〉 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.
Type of Medium:
Online Resource
ISSN:
1662-9779
DOI:
10.4028/www.scientific.net/SSP.130
DOI:
10.4028/www.scientific.net/SSP.130.203
Language:
Unknown
Publisher:
Trans Tech Publications, Ltd.
Publication Date:
2007
detail.hit.zdb_id:
2051138-3
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