Magnetic Carbon Nanofibers Research Articles

Magnetic carbon nanofibers containing uniformly dispersed Fe/Co/Ni nanoparticles as stable and high-performance electromagnetic wave absorbers

Magnetic carbon nanofibers containing uniformly dispersed Fe/Co/Ni nanoparticles (CNF–M) exhibit excellent electromagnetic wave absorption properties from the C-band to the Ku-band.

Magnetic alignment of nickel-coated carbon fibers

Magnetic composites of nickel-coated carbon nanofibers have been successfully fabricated by employing a simple microwave-assisted procedure. The scanning electron microscopy images show that a complete and uniform nickel coating with mean size of 25 nm could be deposited on carbon fibers. Magnetization curves demonstrate that the prepared composites are ferromagnetic and that the coercivity is 96 Oe. The magnetic carbon nanofibers can be aligned as a long-chain structure in an external magnetic field.

Synthesis and characterization of magnetically active carbon nanofiber/iron oxidecomposites with hierarchical pore structures

Polyacrylonitrile (PAN) solution containing the iron oxide precursor iron (III)acetylacetonate (AAI) was electrospun and thermally treated to produce electricallyconducting, magnetic carbon nanofiber mats with hierarchical pore structures. Themorphology and material properties of the resulting multifunctional nanofibermats including the surface area and the electric and magnetic properties wereexamined using various characterization techniques. Scanning electron microscopyimages show that uniform fibers were produced with a fiber diameter of∼600 nm, and this uniform fiber morphology is maintained after graphitization with a fiber diameter of∼330 nm. X-ray diffraction (XRD) and Raman studies reveal that both graphite andFe3O4 crystals are formed after thermal treatment, and graphitization can be enhanced by thepresence of iron. A combination of XRD and transmission electron microscopy experimentsreveals the formation of pores with graphitic nanoparticles in the walls as well as theformation of magnetite nanoparticles distributed throughout the fibers. Physisorptionexperiments show that the multifunctional fiber mats exhibit a high surface area(200–400 m2 g−1) and their pore size is dependent on the amount of iron added and graphitizationconditions. Finally, we have demonstrated that the fibers are electrically conducting as wellas magnetically active.