Synthesis and Characterization of Iron Oxide Nanoparticles Prepared by Electrical Explosion of Fe Wire in Ar–O2 Gas Mixtures

Iron oxide nanoparticles were prepared using a wire explosion method. Pure Fe wire was exploded in Ar­5%O2 ,A r­10%O2 and Ar­ 30%O2 gas mixtures. The variation in the oxygen partial pressure in the explosion chamber resulted in a full spectrum of iron oxide nanoparticles, the sizes of which ranged from 10 to 200nm. The phases in the explosion products were augmented in the order FeO ¼ magnetite (Fe3O4) ¼ maghemite (£-Fe2O3) ¼ hematite (i-Fe2O3) as the oxygen partial pressure was increased. Among the oxide phases, magnetite (Fe3O4) and maghemite (£-Fe2O3) were the major phases, and the identification and relative quantification of both phases was possible through a step-scan and peak deconvolution routine. The presence of the magnetite-maghemite phase mixture was also substantiated by a field-emission transmission electron microscopy (FE-TEM) study on individual particles. The average particle size and phase ratio (maghemite/magnetite) decreased with increasing oxygen partial pressure. [doi:10.2320/matertrans.M2012186]