Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8154214 | Journal of Magnetism and Magnetic Materials | 2017 | 6 Pages |
Abstract
Magnesium ferrite, MgFe2O4, nanoparticles with a mean diameter varying from â¼6 to â¼17 nm were successfully synthesized using a simple thermal decomposition method at different annealing temperatures ranging in between 400 and 600 °C. Pure spinel ferrite nanoparticles were obtained at temperatures lower than 500 °C, while the presence of hematite (α-Fe2O3) impurities was observed at higher temperatures. Single-phase samples show a superparamagnetic behavior at 300 K, the saturation magnetization (Ms) becoming larger with the increase of particles size. The temperature dependence of Ms was explained in terms of surface spin-canting as well as spin wave excitations in the core. Using a modified Bloch law, [Ms(T)=Ms(0)(1âβTα)], we observed a size dependent behavior of the Bloch constant β and the exponent α, whose values increase and decrease, respectively, as the particle size reduces.
Related Topics
Physical Sciences and Engineering
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Condensed Matter Physics
Authors
B. Aslibeiki, G. Varvaro, D. Peddis, P. Kameli,