The new metal-ferrite composite [Fe0.2Co0.8]0.8[Fe2.38Co0.62O4]is obtained by precipitation of ferrous and cobalt chloride in KOH. Furtherheating under vacuum above 400°C shows a cationic exchange between metal andspinel leading to a new composite made up of cobalt metal and cobalt dopedmagnetite.
HTERM and EDX observations have been carried out on both composites, i.e.,before and after vacuum annealing, We show that cationic exchange occursmainly in crystals made up of spinel, CoO and amorphous nanoparticles.