Characteristics of graphene-layer encapsulated nanoparticles fabricated using laser ablation method

摘要

Graphene layer-encapsulated Ni nanoparticles with diameters between 3 and 10 nm were fabricated by laser ablation techniques and deposited directly on the Si substrate at room temperature. It was found from the field-emission type scanning electron microscopy (FE-SEM) and transmission electron mieroscopy(TEM) analyses that any carbon nanotubes were not fabricated in the deposited nano-materials. High-resolution TEM observation showed the core-shell structure of Ni-C particles with crystalline nickel core surrounded by graphite-like layers. The X-ray diffraction(XRD) pattern also revealed that nanoparticles embedded in graphene capsules are crystalline nickel. With these Ni-C nanoparticles, we demonstrated the growth of vertically aligned carbon nanotubes with low spatial density on a silicon substrate by thermal CVD.