Y-junction carbon nanotubes grown by in situ evaporated copper catalyst

Comment on “Intrinsic electron transport properties of carbon nanotube Y-junctions” [Appl. Phys. Lett. 81, 5234 (2002)]

“…1,2 Two-and three-terminal junctions of different type of nanotubes were first proposed in simulations [3][4][5][6][7][8][9][10] and later fabricated in experiments. [11][12][13][14][15][16][17][18][19] The importance of three terminal T-and Y -junction nanotubes arises from the fact that these can provide the framework on which simple nanoscale carbon based transistor, power amplification, or analog logic devices could be designed and fabricated. Initial investigations and proposals, in this case, also were primarily through theoretical modeling and computer simulation based studies.…”

Formation of bamboo-shape carbon nanotubes by controlled rapid decomposition of picric acid

“…The outer diameters and lengths of these normal tubes are in the range of 12-50 nm and 0.5-40 μm, respectively. When loading density of PA decreases from 0.2 to 0.05 g/cm 3 , the total yield of CNTs decreases sharply from 80% to 20% (compared to total carbons) whereas C bamboo /C normal ratio seems to have a slight increase (samples 4, 8, 9 in Table 1). These results suggest that the formation of bamboo-shape CNTs is associated with relatively low temperatures since the present system is self-heated by the chemical-thermal energy transformation of PA and the loading density of PA determines the system temperature.…”

“…The optimal conditions for the formation of bamboo-shape tubes are typically at Co(AC) 2 /PA and paraffin/PA ratios of 1/10 and 1/3, respectively, and at a PA loading density of 0.2 g/cm 3 . Under this condition, almost all of the formed CNTs are in bamboo shape (Fig.…”

“…Recently, carbon nanotubes with special structures such as bamboo-shape [1] and [2], Yjunctions [3], sea urchins [4] and coils [5] have attracted much attention. As the most common member of this family, bamboo-shape CNTs, constructed by many separated hollow compartments, have been frequently investigated to explore their unique structure-associated properties and to understand the relationship between their formation and the growth of normal tubes that exhibit continuous hollow channels.…”

Continuous Synthesis of Y‐Junction Carbon Nanotubes by Catalytic CVD

“…[11] More significantly, it has been possible to prepare Y-junction CNTs by the pyrolysis of nickelocene in the presence of thiophene at 1273 K. [12] Y-junction CNTs have also been formed by hot tantalum-filament CVD using an evaporated copper catalyst, and acetone as the carbon source. [13] Here, we report an alternative method for producing Y-junction CNTs involving catalytic (C)CVD. Cupric acetate was dissolved in methanol and the solution sprayed into a reaction chamber set at a high temperature.…”