Investigation of the reactivity of AlCl3 and CoCl2 toward molten alkali-metal nitrates in order to synthesize CoAl2O4

Noura Ouahdi , Sophie Guillemet (1) , Jean-Jacques Demai (1) , Bernard Durand (1) , Lahcen Er-Rakho , Redouane Moussab , Azzeddine Samdi

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

Cobalt aluminate CoAl2O4 powder, constituted of nano-sized crystallites, is prepared, involving the reactivity of AlCl3 and CoCl2 with molten alkali-metal nitrates. The reaction at 450 °C for 2 h leads to a mixture of spinel oxide Co3O4 and amorphous γ-Al2O3. It is transformed into the spinel oxide CoAl2O4 by heating at 1000 °C. The powders are mainly characterized by XRD, FTIR, ICP, electron microscopy and diffraction, X-EDS and diffuse reflection. Their properties are compared to those of powders obtained by solid state reactions of a mechanical mixture of chlorides or oxides submitted to the same thermal treatment.

Mots clés: Cobalt aluminate; Spinel structure; Reactions in molten salts; Nanomaterials; X-ray techniques; Electron microscopy

Domaines: Matériaux

Noura Ouahdi, Sophie Guillemet, Jean-Jacques Demai, Bernard Durand, Lahcen Er-Rakho, et al.. Investigation of the reactivity of AlCl3 and CoCl2 toward molten alkali-metal nitrates in order to synthesize CoAl2O4. Materials Letters, 2005, 59 (2-3), pp.334-340. ⟨10.1016/j.matlet.2004.10.013⟩. ⟨hal-03601613⟩