Abstract
Fe3O4/carbon composite nanoparticles were prepared using polystyrene as the carbon source, with a household microwave oven providing the required energy to produce plasma in a partially-evacuated reaction vessel, leading to the high temperatures required for carbonization of the carbon source and formation of nanoparticles. In this process, magnetite nanoparticles actively catalyzed the formation of carbon nanofibers. The resulting composite retained the magnetic properties after this process, which is potentially very useful for producing new additives for electromagnetic shielding nanocomposites.