Controlled synthesis of CoFe2O4 nano-octahedra

André-Luis Lopes-Moriyama (1, 2) , V. Madigou (2) , Carlson Pereira de Souza (3) , Christine Leroux (2)

1 LMNRC
2 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
3 LMNRC

Nano-octahedral grains of cobalt ferrite (CoFe2O4) with size around 20 nm were synthesized by a hydrothermal route. X-rays and electron diffraction, along with scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy and thermogravimetric analysis were used to characterize the powders. Images and simulations of high-resolution electron microscopy allowed the identification of the shape of the grains. Process parameters such as temperature and time of reaction, reagents concentration, and pH of the reacting medium were optimized. The surfactant cetyltrimethylammonium bromide (CTAB) hindered the formation of goethite, which favored the production of a pure CoFe2O4 powder. The oxidation state of cobalt atoms on the ferrite structure was also influenced by CTAB. The control of the shape of the grains was associated mainly to the nature of the precipitating agent.

Mots clés: electron microscopy; Hydrothermal synthesis; nanoparticles; cobalt ferrite; shape of nanoparticles; electron microscopy.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

André-Luis Lopes-Moriyama, V. Madigou, Carlson Pereira de Souza, Christine Leroux. Controlled synthesis of CoFe2O4 nano-octahedra. Powder Technology, 2014, 256, pp.482. ⟨10.1016/j.powtec.2014.01.080⟩. ⟨hal-01053694⟩