Growth and characterization of carbon nanotubes on constantan (Cu–Ni–Mn alloy) metallic substrates without adding additional catalysts

In this study, metallic constantan ( Cu 55 – Ni 44 – Mn 1 wt % ) alloy substrates were investigated as an alternate choice of substrates to grow carbon nanotubes (CNTs). No additional catalysts were used other than the as-rolled and annealed substrates to process CNTs on them. High density CNT growth was observed to take place on these substrates when suitable conditions were used in a thermal chemical vapor deposition (CVD) furnace with C 2 H 2 as the carbon precursor. Scanning electron microscopy and transmission electron microscopy on these samples indicated the presence of several micron long CNTs ranging in 20 – 100 nm in diameter. Raman spectra taken from the samples confirmed the presence of G band peaks (peak at ∼ 1580 cm − 1 ) and D band peaks (peak at ∼ 1320 cm − 1 ) commonly observed in CVD grown multiwall CNT samples with varying intensity ratios depending on the processing conditions.