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