Zk. Tang et al., Mono-sized semiconducting carbon nanotubes formed in 1-nm-sized channels of aluminophosphate single crystal, J KOR PHYS, 34, 1999, pp. S7-S11
Carbon nanotube materials can now be produced in macroscopic quantities. Ho
wever, the raw material has a disordered structure and unsorted size, which
restrict investigations of both the properties and applications of the nan
otubes. In this paper, an alternative approach to the synthesis of mono-siz
ed and parallel-aligned single wall carbon nanotubes (SWCNs) is reported. T
he SWCNs are formed in l-nm-sized channels of aluminophosphate zeolite crys
tallites by pyrolysis of tripropylamine molecules. As verified by tunnel el
ectron microscopy and micro-Raman scattering, the SWNT is of zigzag structu
re. Electrical transport properties of the SWNT are measured in the tempera
ture range of 0.3 K similar to 300 K. The temperature-dependent de conducti
vity shows that the SWNT is an intrinsic semiconductor with a narrow band-g
ap of 52 meV. The well-aligned and mono-sized SWCNs allow us to make more c
ontrolled characterization as well as open a door to potential nano-technol
ogical application for the novel electronic nanotube system.