EFFECT OF FORMATION CONDITIONS ON THE STRUCTURE, MORPHOLOGY AND MAGNETIC PROPERTIES OF NANOSIZED MIIFe (M = Mn, Co, Ni) AND Fe2O3

A study was carried out on the conditions of formation of highly crystalline, superparamagnetic, nanosized oxides, M Fe^ II 2^ III O4 and gamma-Fe2O3 (4.9-11.7 nm) by the thermal decomposition of complexes [MFe2O(CH3CO2)6(H2O)3] (M = Mn, Fe, Co, Ni) in tetraethylene glycol. The presence of surfactants leads to a decrease in the size and size distribution of the nanoparticles formed, while the use of microwave radiation significantly reduces the time for formation of the nanocrystalline oxides. The magnetic measurements showed ferrimagnetic ordering in the nanoparticles studied and their superparamagnetic behavior.