Formation of self-aligned carbon nanotube films by surface decomposition of silicon carbide

Investigating the Outskirts of Fe and Co Catalyst Particles in Alumina-Supported Catalytic CVD Carbon Nanotube Growth

“…Oxygen has been shown to exist at the surface of the SiC where the sp 2 carbon anchors onto the crystal. 14,29 The evidence presented here shows a direct interaction between the graphitic roots of a carbon nanotube and an ␣-alumina support. On the basis of these findings, it cannot be exclusively decided if carbon preferentially binds at oxygen sites.…”

“…However, the argument for oxygen is compelling because oxygen is known to enhance graphitization and activate catalysts in CNT formation. 10,14,30 Furthermore, as we have shown, the use of non-oxide supports results in the formation of non-uniform structures. The need to replenish oxygen at the substrate surface would offer an additional explanation for the role of H 2 O in the supergrowth of CNTs.…”

“…13 It is worth noting that the use of SiC for CNT synthesis via the high temperature decomposition of SiC requires oxygen in the reaction. 14 In addition, the use of metal oxide catalysts 10,15Ϫ17 is emerging as an attractive alternative to metal catalysts due to their potential integration with Si technology and easier removal from asproduced CNT samples (purification). The catalytic activity of metal oxides opens up a key question as to whether the oxides, when used as supports for metal catalysts in CNT synthesis, play an active catalytic role in the formation of the CNT.…”

Initial Growth Process of Carbon Nanotubes in Surface Decomposition of SiC

“…In the growth of graphene, in general, the temperature of SiC is quickly increased to the growth temperature, typically, about several minutes to ~1400ºC (Gamara et al, 2008). On the other hand, in the CNT growth by surface decomposition, the heating rate is typically 1-15ºC/min (Kusunoki et al 1999(Kusunoki et al , 2002 and much slower than that in the graphene growth. This low heating rate might be necessary to enhance the migration of carbon atoms, assembling and leading to formation of carbon nanocaps.…”

“…In early studies, Kusunoki et al proposed a chemical reaction process for CNT growth by surface decomposition of SiC as follows (Kusunoki et al 1999):…”