Synthesis of carbon nanocoils by microwave CVD

Abstract

The carbon nanocoil is an interesting kind of nanomaterial, which is expected tohave various novel applications in microelectronics, microelectromechanicalsystems (MEMS) and bioMEMS due to its nanosize coil morphology. Carbonnanocoils were synthesized by catalytic pyrolysis of acetylene over 2.2–3.0 µm Niparticles at 600°C in a microwave chemical vapour deposition (CVD) system.Microwave CVD derived nanocoils are rather uniform with an average coildiameter of 110–170 nm, fibre diameter of 80–120 nm and pitch of around 130–200nm. The effects of reaction temperature, the size of Ni catalyst and the flow rateof acetylene were examined. Additionally, the growth mechanism of carbonnanocoils was studied. It was found that two individual carbon nanocoils extrudefrom the same Ni particle in the same direction as straight fibres at thebeginning and then bend to grow into nanocoils in opposite directions.