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Structure studies on nanocrystalline MgO powders prepared by sol-gel method dried under different conditions
|Grzegorz Dercz 1, Krystian Prusik 1, Lucjan Pająk 1, Roman Pielaszek 2, Janusz J. Malinowski 3, Wojciech Pudło 4|
1. University of Silesia, Institute of Material Science, Bankowa 12, Katowice 40-007, Poland
The structure studies were performed on tree nanocrystalline MgO powders prepared by sol-gel technique, which produce high purity, chemically homogeneous materials with relatively high specific surface areas. Magnesium methoxide was used as MgO precursor. The wet gels were dried under different conditions to prepare a hydrated form of MgO. The applied dry conditions yielded two aerogels and one xerogel with periclase phase, the only crystalline form of magnesium oxide.
The X-ray diffraction and scanning electron microscopy were used as the tools of structure analysis. The Toraya PRO-FIT procedure and Rietveld refinement method were applied at X-ray data analysis. PRO-FIT procedure enables the determination of parameters of individual diffraction lines and applies Pearson VII function for the description of line profiles. This function appeared to be the most useful also at Rietveld refinement procedure.
The average crystallite size of the studied MgO powders estimated from Scherrer formula was in the range 5.5 - 7.5 nm. The crystallite size distributions were also determined using FW(1/5 and 4/5)M method proposed by R. Pielaszek. The obtained at Rietveld refinement Rwp, Rexp and S fitting parameters, seem to be satisfactory due to the nanosize of MgO crystallites and since the presence of small amount of amorphous phase is very probable.
Presentation: Poster at E-MRS Fall Meeting 2006, Symposium B, by Grzegorz Dercz
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-19 14:01 Revised: 2009-06-07 00:44