Synthesis of different magnetic carbon nanostructures by the pyrolysis of ferrocene at different sublimation temperatures

Various magnetic nanostructures such as Fe nanoparticles (Fe-NPs) adhering to single-walled carbon nanotubes, carbon-encapsulated Fe-NPs, Fe-NP decorated multi-walled carbon nanotubes (MWCNTs), and Fe-filled MWCNTs have been synthesized by the pyrolysis of pure ferrocene. It is found that the formation of the nanostructures can be selectively controlled by simply adjusting the sublimation temperature of ferrocene, while keeping all other experimental parameters unchanged. Magnetic characterization reveals that these nanostructures have an enhanced coercivity, higher than that of bulk Fe at room temperature. Based on the experimental results, the formation mechanism of the nanostructures is discussed in detail.