Impact of ignition temperature on particle size and magnetic properties of CoFe2O4 nanoparticles prepared by self-propagated MILD combustion technique

Autor: Madeswaran Saminathan, D. Rajan Babu, Venkatesan Kaliyamoorthy
Rok vydání: 2016
Předmět:
Zdroj: Journal of Magnetism and Magnetic Materials. 418:280-288
ISSN: 0304-8853
DOI: 10.1016/j.jmmm.2016.05.025
Popis: We prepared nanocrystalline CoFe 2 O 4 by changing its ignition temperatures, using moderate and intense low-oxygen dilution (MILD) combustion technique. The effect of ignition temperature on the particle size and its magnetic behavior was investigated by HR-TEM and VSM respectively. We observed a vast change in the structural behavior and the magnetic properties of the prepared samples. X-ray diffraction studies revealed that the resultant samples had single phase with different grain sizes from 23±5 nm to 16±5 nm, which was understood by observing the growth of the grains through heat released from the combustion reaction. FE-SEM analysis showed high porosity with heterogeneous distribution of the pore size based on the adiabatic temperature and EPMA analysis, which confirmed the elemental compositions of the prepared samples. The saturation magnetization values measured at room temperature, employing vibrating sample magnetometer (VSM) decreased gradually from 50 to 34 emu/g when the ignition temperature was increased from 243 °C to 400 °C. Some of Fe ions on the B sites moved periodically to the A sites because of quenching treatment. The presence of Fe 2+ ions in the existing ferrite structure ruled the magnetic behavior of the sample, as confirmed by the Mossbauer analysis.
Databáze: OpenAIRE
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