High density of multiwalled carbon nanotubes observed on nickel electroplated copper substrates by microwave plasma chemical vapor deposition

High density and long multiwalled carbon nanotubes are deposited using nickel clusters formed from an electrodeposited nickel coating treated by ammonia. Tubes of length 40–50 μm having bamboo shaped structure are aligned nearly parallel to the copper substrate. The inner diameter of the tubes is in the range 20–50 nm. The selected area and nano area diffraction spots clearly show the crystalline nature of nickel clusters. At some locations of the samples in the vicinity of graphite layers, Ni3C phase is also detected. The formation of the Ni3C phase that is unstable at high temperature supports the idea of a vapor–liquid–solid (VLS) mechanism for the growth of the tubes.