Nature 363, 603 - 605 (17 June 1993); doi:10.1038/363603a0

Single-shell carbon nanotubes of 1-nm diameter

Sumio Iijima & Toshinari Ichihashi

Fundamental Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, Ibaraki 305, Japan

CARBON nanotubes¹ are expected to have a wide variety of interesting properties. Capillarity in open tubes has already been demonstrated^2–5, while predictions regarding their electronic structure^6–8 and mechanical strength⁹ remain to be tested. To examine the properties of these structures, one needs tubes with well defined morphologies, length, thickness and a number of concentric shells; but the normal carbon-arc synthesis^10,11 yields a range of tube types. In particular, most calculations have been concerned with single-shell tubes, whereas the carbon-arc synthesis produces almost entirely multi-shell tubes. Here we report the synthesis of abundant single-shell tubes with diameters of about one nanometre. Whereas the multi-shell nanotubes are formed on the carbon cathode, these single-shell tubes grow in the gas phase. Electron diffraction from a single tube allows us to confirm the helical arrangement of carbon hexagons deduced previously for multi-shell tubes¹.

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