Production of iron-oxide nanoparticles by laser-induced pyrolysis of gaseous precursors

Laser-assisted pyrolysis in a continuous flow reactor has been applied to synthesise iron-oxide nanoparticles. The scope of the present contribution was to investigate the possibility of increasing the reaction yield in order to obtain powder amounts suitable for practical applications. To this aim, a gas mixture containing Fe(CO)5 and N2O has been submitted to CO2 c.w. laser pyrolysis. As a reaction sensitiser gas, SF6 has been preferred to C2H4 to avoid ethylene fragmentation in N2O presence and the formation of iron carbides. Due to unexpected SF6 dissociation, the synthesis process led to the preferential formation of iron fluoride compounds. Powder samples, submitted to calcining treatment (400°C, 3 h), showed an almost complete transformation to α- and γ-iron oxides retaining the nanostructure feature of the powder.