Fe/Fe3O4 nanocomposite powders with giant high magnetization values by high energy ball milling

Abstract

The present work reports on the relatively higher saturationmagnetization values of Fe/Fe3O4 nanocomposites. For example, the nanocomposites of Fe obtained after milling for 10 hwith 5, 10 and 15wt% of Fe3O4 had displayed saturation magnetization values of 210, 238 and 216 Am2 kg-1, respectively, in contrast to 218 Am2 kg-1 of bulk Fe. Similarly, the maximum magnetization values for the nanocomposites after 20 and 30 h of milling were 215 and 190Am 2 kg-1 for the sample containing 5 and 15 wt% of Fe3O4, respectively. The values of HC and Mr suggest that nanocomposites exhibit soft ferromagnetic behaviour. The ball milling also reduced the crystallite and particle size of Fe from microndimension to nanometres. Thiswas confirmed fromX-ray diffraction, transmission electronmicroscopy and scanning electron microscopy analyses. The crystallite size of pure Fe decreased to 35, 20 and 19 nm, respectively, for the samples having 5, 10 and 15 wt% of Fe3O4 after 10 h of milling. The crystallite size decreased further with increased milling time.