Abstract
Fine particles of cerium substituted hematite with different compositions were prepared by the sol-gel method from the aqueous solution of their corresponding metal salts. Mixed hydroxides of Fe3+ and Ce 4+ were obtained by reacting aqueous NH3 with the aqueous solution of FeCl3 and Ce(NH3)2(NO 3)6 at pH 2.5-3.0) and they were heat treated at different temperatures between 400 and 1200°C in air for 2 h to get the mixed oxide product. Thermal analysis and X-ray diffraction studies revealed the coexistence of Fe2O3 and CeO2 phase separately up to 900°C, and covalent interaction between them above 1000°C, which was evidenced by the shifting of the XRD peaks. Unit cell parameters and the cell volumes (V) of the samples derived between 1000 and 1200°C were found to be in the range a = 5.045-5.048 ± 0.007 Å, c = 13.774-13.815 ± 0.041 Å and V = 303.608-304.874 Å3 respectively. It was observed that both the lattice parameters and the cell volumes were higher than that of the pure α-Fe2O3 (a = 5.036 Å, c = 13.749 Å, V = 301.976 Å3) system. The expansion of lattice parameters further supported the incorporation of the large Ce 4+ ion into the α-Fe2O3 matrix. The lattice parameter increased with increasing Ce4+ ion loading. FESEM studies showed the growth of the particles with increasing temperature though it was suppressed due to the presence of Ce4+ ions as compared to the pure system.
Original language | English |
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Pages (from-to) | 3783-3787 |
Number of pages | 5 |
Journal | Materials Letters |
Volume | 59 |
Issue number | 28 |
DOIs | |
Publication status | Published - Dec 1 2005 |
Keywords
- Cerium substituted FeO
- Crystal growth
- Sol-gel method
- XRD
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering