Growth of vertically aligned carbon nanotube bundles using atmospheric-pressure microplasma

Vertically aligned bundles of multiwalled carbon nanotubes (MWNTs) were grown on the tip of a phi 0.5 mm nickel wire using an atmospheric-pressure microplasma (AP mu P) generated by a RF-powered pipe electrode. A CH4 and H-2 gas mixture was used for the source gas, and the nickel wire used as the substrate was negatively biased to heat it by ion bombardment. At a ratio of CH4 : H-2 = 1 : 35, a RF power of 6 W, a DC bias voltage of - 100 V and a growth time of 2 min, the tip of the nickel wire was covered by bamboo-like MWNT bundles, whose diameter and length were about 600 nm and 2-3 mu m, respectively. Each bundle consisted of about 1500 tubes with diameters of 10-25 nm. The growth temperature of the MWNT bundles was approximately 500 degrees C.