Synthesis and characterization of superparamagnetic composite nanorings

Superparamagnetic nanorings of polystyrene/Fe3O4 composite were synthesized by miniemulsion polymerization. The nanoring structure was characterized by using transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. The results of X-ray diffraction identified the magnetic constituent of as-synthesized composite nanorings as Fe3O4. The magnetization measurement showed typical superparamagnetic characteristics of polystyrene/Fe3O4 nanorings.