Thermally-grown carbon nanotubes (CNTs) were observed with varying parameters to observe their change in shape and line resistivities. The thicknesses of the catalyst and growth temperatures were varied during CNT growth using a thermal CVD process to obtain CNTs with minimum line resistivities. It was observed that the diameter of CNTs increased as the thickness of the Ni catalyst increases at increasing growth temperatures. Moreover, the resistivity of CNTs increased with a decrease in the growth temperature, and a growth temperature of 800 oC and 10 nm of Ni catalyst are the optimal conditions for the growth of CNTs with the lowest resistivity. In this condition, the lowest resistivity was measured to be 7.48 × 10−2 Ω·cm. The line resistivity was measured from the substrate where the CNTs were grown, not that of each tube. These resistivity values are unique for use as electrodes since no vertically-grown CNTs with a thermal CVD process have had their resistivity values reported. Therefore, CNTs grown with a thermal CVD process showed their potential to be used as electrodes.

Keywords: Carbon, Nanotubes, Grain growth, Sintering, Electrical properties