Ž . Diamond and Related Materials 10 2001 11851189 Arc plasma jet method producing single-wall carbon nanotubes Yoshinori Ando a, , Xinluo Zhao b , Kaori Hirahara b , Kazutomo Suenaga b , Shunji Bandow b , Sumio Iijima a,b a Department of Materials Science and Engineering, Meijo Uni ersity, Shiogamaguchi 1-501, Tenpaku-ku, Nagoya 468-8502, Japan b JST-ICORP, c  o Department of Materials Science and Engineering, Meijo Uni ersity, Shiogamaguchi 1-501, Tenpaku-ku, Nagoya 468-8502, Japan Abstract Ž . The DC arc plasma jet method was newly developed for the mass-production of single-wall carbon nanotubes SWNTs . The quantity of cathode deposit was efficiently reduced by this method, and the production rate of cotton-like soot including SWNTs was significantly higher than that by conventional DC arc discharge evaporation. Investigation by using scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy indicated that more than 50% of the cotton-like soot was the fibrous bundles of SWNTs with diameters of 1.34 1.53 nm.  2001 Elsevier Science B.V. All rights reserved. Keywords: Single-wall carbon nanotubes; Arc plasma jet evaporation; Scanning electron microscopy; Transmission electron microscopy; Raman spectroscopy 1. Introduction Ž .   Single-wall carbon nanotubes SWNTs 1,2 are a kind of fascinating nanostructured materials, and may be a candidate of new semiconductor materials because they can be either metallic or semiconducting depend-   ing on their diameter and chirality 3  8 . High yield of SWNTs can be realized by laser ablation as rubbery  soot 9 or by conventional DC arc discharge evapora-   tion as collar deposits 10 . In the latter case, SWNTs can be found in the cotton-like soot also, but not in the cathode deposit. Usually, more than 60% of evaporated materials from the metal-doped graphite anode directly  Corresponding author. Tel.: 81-52-832-1151; fax: 81-52-832- 1170. Ž . E-mail address: yando@meijo-u.ac.jp Y. Ando . run onto the surface of cathode and form the cathode deposit there. In order to produce SWNTs efficiently by arc dis- charge, it is necessary to reduce the quantity of cathode deposit and increase the yield of SWNTs in cotton-like Ž . soot. We developed a new DC arc plasma jet APJ method for the mass-production of SWNTs. In our experiments, the angle between the cathode and the anode was changed from 180 to 30, and a carbon APJ was formed in the evaporation process of the metal- doped graphite anode. The percentage of cathode de- posit to evaporated materials from the metal-doped graphite anode was successfully reduced to less than 20%, and the production rate of cotton-like soot was significantly higher than that by conventional DC arc discharge evaporation. Investigation by scanning elec- Ž . tron microscopy SEM , high-resolution transmission Ž . electron microscopy HR-TEM and Raman spectro- 0925-963501$ - see front matter  2001 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 9 2 5 - 9 6 3 5 00 00513-6