%0 Journal Article
	%A Jiri Plocek and  Petr Holec and  Simona Kubickova and  Barbara Pacakova and  Irena Matulkova and  Alice Mantlikova and  Ivan Nemec and  Daniel Niznansky and  Jana Vejpravova
	%D 2014
	%J International Journal of Chemical and Molecular Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 95, 2014
	%T Stabilization of Transition Metal Chromite Nanoparticles in Silica Matrix
	%U https://publications.waset.org/pdf/9999702
	%V 95
	%X This article presents summary on preparation and
characterization of zinc, copper, cadmium and cobalt chromite
nanocrystals, embedded in an amorphous silica matrix. The
ZnCr2O4/SiO2, CuCr2O4/SiO2, CdCr2O4/SiO2 and CoCr2O4/SiO2
nanocomposites were prepared by a conventional sol-gel method
under acid catalysis. Final heat treatment of the samples was carried
out at temperatures in the range of 900−1200 ◦C to adjust the
phase composition and the crystallite size, respectively. The resulting
samples were characterized by Powder X-ray diffraction (PXRD),
High Resolution Transmission Electron Microscopy (HRTEM),
Raman/FTIR spectroscopy and magnetic measurements. Formation
of the spinel phase was confirmed in all samples. The average size of
the nanocrystals was determined from the PXRD data and by direct
particle size observation on HRTEM; both results were correlated.
The mean particle size (reviewed by HRTEM) was in the range from
∼4 to 46 nm. The results showed that the sol-gel method can be
effectively used for preparation of the spinel chromite nanoparticles
embedded in the silica matrix and the particle size is driven by the
type of the cation A2+ in the spinel structure and the temperature
of the final heat treatment. Magnetic properties of the nanocrystals
were found to be just moderately modified in comparison to the bulk
phases.

	%P 1219 - 1228