Probing the structural, crystalline, and electrical properties of carbon nanotubes grown on nickel filled carbon nanofibers

Carbon nanotubes (CNTs) were produced on nickel filled carbon nanofiber substrates. The carbon source was provided by irradiation of pyrolytic graphite. The mean outer diameter of the CNTs, which was identified as multiwalled carbon nanotubes, varies in the range of 5-15 nm. The crystallographic structures, chemical compositions, and bond structures of the carbon materials were investigated. The modified crystal structure was attributed to better lattice arrangement resulting from increased lattice vibration at high substrate temperature. The improved electron field emission behavior of the obtained sample at higher temperature could be caused by the increasing effective emission sites.