Two types of carbon nanocomposites: Graphite encapsulated iron nanoparticles and thin carbon nanotubes supported on thick carbon nanotubes, synthesized using PECVD

In this work, graphite encapsulated Fe nanoparticles and thin carbon nanotubes (CNTs) supported on the pristine CNTs, respectively, were synthesized using plasma enhanced chemical vapor deposition via efficiently controlling the flow rate of discharging CH₄ and H₂ gas. The properties of the obtained hybrid materials were characterized with superconducting quantum interference and field emission measurements. The results showed that the encapsulated Fe nanoparticles had diameters ranging from 1 to 30 nm, and this hybrid nanocomposite exhibited a ferromagnetic behavior at room temperature. Thin CNTs with an average diameter of 6 nm were attached to the surface of the prepared CNTs, which exhibited a lower turn-on field and higher emission current density than the pristine CNTs. The Fe nanoparticles either encapsulated with graphite or used as catalyst for thin CNTs growth were all originated from the pyrolysis of ferrocene.