Magnetic studies of polymer-coated Fe nanoparticles synthesized by microwave plasma polymerization

Abstract
Static and dynamic magnetic experiments were conducted on polymer-coated Fe nanoparticles synthesized by a microwave plasma method. Transmission electron microscopy indicates the formation of 15–20 nm particles and agglomerated clusters. The field-dependent magnetization (M–H) data show the presence of sharp switching at low fields (∼60 Oe) followed by a gradual approach to saturation. A saturation magnetization of M s ∼80 emu/g is obtained for the nanopowder. Dynamic transverse susceptibility using a radio-frequency resonant method provides evidence for sharp switching fields and a broad distribution in anisotropy fields. These results indicate that the polymer coating plays an effective role in the underlying magnetic response of the particles.