Novel method for synthesis of Fe core and C shell magnetic nanoparticles

Using a newly developed method, carbon-encapsulated iron (Fe) nanoparticles were synthesized by plasma due to ultrasonication in toluene. Fe core with carbon shell nanoparticles were characterized using Transmission Electron Microscopy (TEM) and High Resolution Transmission Electron Microscopy (HRTEM). Fe nanoparticles of diameter 7-115 nm are encapsulated by 7-8 nm thick carbon layers. There was no iron carbide formation observed between the Fe core and the carbon shell. The Fe nanoparticles have body centered cubic (bcc) crystal structure. Synthesized nanoparticles showed a saturation magnetization of 9 A m2/kg at room temperature. After thermal treatment crystalline order of the nanoparticles improved and saturation magnetization increased to 24 A m2/kg. We foresee that the carbon-encapsulated Fe nanoparticles are biologically friendly and could have potential applications in Magnetic Resonance Imaging (MRI) and photothermal cancer therapy.