Part of the book: Carbon Nanotubes
Helical carbon nanofibers (HCNFs), including carbon nanocoils (CNCs), carbon nanotwists, and multi-walled CNCs, can be synthesized by chemical vapor deposition (CVD). HCNFs are predicted to have a high mechanical strength and hence are expected to have a use in nanodevices such as electromagnetic wave absorbers and sensors. For nanodevice applications, it is necessary to synthesize HCNFs in high yield and purity. In this chapter, I focus on CNCs and describe its history, expected application, and synthesis method. Finally, I introduce the author’s recent studies on the improvement of the purity of CNCs by improving CVD conditions. A CNC layer with a thickness of larger than 40 μm was grown from a triple layer of SnO2/Fe2O3/SnO2 catalyst on a substrate, and the CNC purity increased to 81 ± 2%.
Part of the book: Chemical Vapor Deposition for Nanotechnology