Journal
JOURNAL OF SOLID STATE CHEMISTRY
Volume 191, Issue -, Pages 136-141Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jssc.2012.03.022
Keywords
CeO2; epsilon-Fe2O3; High coercivity; Iron oxide polymorphs; Phase transitions
Funding
- Grant Agency of the Czech Republic [P108/10/1250]
- Ministry of Education of the Czech Republic [MSM0021620857]
- Grant Agency of the Charles University [146510]
Ask authors/readers for more resources
We have investigated the processes leading to the formation of the Fe2O3 and CeO2 nanoparticles in the SiO2 matrix in order to stabilize the epsilon-Fe2O3 as the major phase. The samples with two different concentrations of the Fe were prepared by sol-gel method, subsequently annealed at different temperatures up to 1100 degrees C, and characterized by the Mossbauer spectroscopy, Transmission Electron Microscopy (TEM), Powder X-ray Diffraction (PXRD), Energy Dispersive X-ray analysis (EDX) and magnetic measurements. The evolution of the different Fe2O3 phases under various conditions of preparation was investigated, starting with the preferential appearance of the gamma-Fe2O3 phase for the sample with low Fe concentration and low annealing temperature and stabilization of the major epsilon-Fe2O3 phase for high Fe concentration and high annealing temperature, coexisting with the most stable alpha-Fe2O3 a phase. A continuous increase of the particle size of the CeO2 nanocrystals with increasing annealing temperature was also observed. (C) 2012 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available