NANOSCOPIC COBALT FERRITE PARTICLES BY SONOLYSIS OF METAL ACETYLACETONATE COMPLEXES
| Authors | |
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| Year of publication | 2009 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Previously we studied the preparation of Fe2O3 and Co3O4 nanoparticles by sonolysis of 2,4/pentanedionato complexes, M(acac)n, M = Fe, Co. Now we continue this research with the preparation of mixed metal oxide CoFe2O4. Sonochemical decompositon of mixtures of M(acac)n by high intensity ultrasound lead to amorphous Co ferrite nanoparticles containing organic matrix. The sonochemical reactivity of precursors was: Co(acac)2 > Fe(acac)3 > Co(acac)3. The XRD data showed that phase-pure CoFe2O4 were obtained for Co:Fe ratios of 1:1.3 to 1:2.0. Variable amounts of added water allowed control of the organics content and the BET surface area (up to 218 m2 g-1). SEM was used to examine the particle shape, size, and size distribution. The organic groups present in the powders were identified by IR and MS as acetate groups. TEM study showed the amorphous state of the sonochemical oxide product and its crystallization above 300 oC in agreement with the results of TG/DSC. The HT-XRD also revealed the spinel crystallization on heating. A small particle size below 20 nm of the crystalline CoFe2O4 is retained up to 600 oC. The delayed crystal growth is ascribed to the protective action of a thin surface layer of pyrolyzed organics. |
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