Structural Analysis of Carbon Nanofibres Synthesised at Room Temperature

Structural characteristics of carbon nanofibres synthesised using radio frequency plasma enhanced chemical vapour deposition (PECVD) and radio frequency assisted microwave PECVD at room temperature were determined using transmission electron microscopy and Raman analysis. The material was generated by the catalytic growth of carbon nanofibres at room temperature using an industry standard radio frequency (13.56 MHz) PECVD and custom designed microwave combined radio frequency PECVD. The thermal energy requirements for the growth were substituted by plasma decomposition of methane upon a nickel catalyst. Room temperature synthesis conditions offer the advantage of growing carbon nanofibres and nanotubes on different temperature sensitive substrates, such as organic materials, plastics and other polymers over relatively large areas. Carbon nanofibres grown using radio frequency combined microwave PECVD exhibit branching during the growth thus forming "Y"-shaped junctions. The interconnecting networks formed by the branched carbon nanofibres could be useful for nanoelectronics applications. The characteristic D and G peaks were observed in the Raman spectra and their intensity ratio and peak width were compared. Electron microscopy analysis provides evidence for a "tip" growth model, with the nickel catalyst particle attached to the tip of the nanofibre.