title: Chirality specific and spatially uniform synthesis of single-walled carbon nanotubes from a sputtered Co-W bimetallic catalyst.
abstract: Synthesis of single-walled carbon nanotubes (SWNTs) with well-defined atomic arrangements has been widely recognized in the past few decades as the biggest challenge in the SWNT community, and has become a bottleneck for the application of SWNTs in nano-electronics. Here, we report a selective synthesis of (12, 6) SWNTs with an enrichment of 50%-70% by chemical vapor deposition (CVD) using sputtered Co-W as a catalyst. This is achieved under much milder reduction and growth conditions than those in the previous report using transition-metal molecule clusters as catalyst precursors (Nature, 2014, 510, 522). Meanwhile, in-plane transmission electron microscopy unambiguously identified an intermediate structure of Co6W6C, which is strongly associated with selective growth. However, most of the W atoms disappear after a 5 min CVD growth, which implies that anchoring W may be important in this puzzling Co-W system.
authors.affiliation: Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan. maruyama@photon.t.u-tokyo.ac.jp xiangrong@photon.t.u-tokyo.ac.jp.
authors.forename: Hua
authors.initials: H
authors.lastname: An
authors.forename: Akihito
authors.initials: A
authors.lastname: Kumamoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takezaki
authors.forename: Shinnosuke
authors.initials: S
authors.lastname: Ohyama
authors.forename: Yang
authors.initials: Y
authors.lastname: Qian
authors.forename: Taiki
authors.initials: T
authors.lastname: Inoue
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ikuhara
authors.forename: Shohei
authors.initials: S
authors.lastname: Chiashi
authors.forename: Rong
authors.initials: R
authors.lastname: Xiang
authors.forename: Shigeo
authors.initials: S
authors.lastname: Maruyama