Phase transformation mechanism of carbon cluster to fiber

To rapidly grow carbon nanometer fiber in large area,the formation,transformation and the physical and chemical reactive mechanism of carbon nanometer fiber were investigated.Carbon nanofiber films were deposited on glass substrates by the method of plasma-enhanced chemical vapor deposition(PECVD) using CH4 as reactive gas and FeCl2 as catalyst.The surface morphology of the carbon nanometer films was observed by scanning electron microscopy(SEM),and the structure composition was analyzed by Raman spectra.The results show that without catalyst the film consists of carbon nanometer clusters,but it presents fiber-like growth when the substrate is coated with catalyst.The fibers are characteristics of the structure of graphite.Among the growth conditions of temperature,pressure and catalyst,catalyst plays a key role in the orientation growth of carbon fiber.Adjusting the concentration and distribution of the catalysts can effectively change the density and distribution of the fibers.