title: Controlled synthesis of a large fraction of metallic single-walled carbon nanotube and semiconducting carbon nanowire networks.
abstract: Controlled synthesis of both single-walled carbon nanotube and carbon nanowire networks using the same CVD reactor and Fe/Al(2)O(3) catalyst by slightly altering the hydrogenation and temperature conditions is demonstrated. Structural, bonding and electrical characterization using SEM, TEM, Raman spectroscopy, and temperature-dependent resistivity measurements suggest that the nanotubes are of a high quality and a large fraction (well above the common 33% and possibly up to 75%) of them are metallic. On the other hand, the carbon nanowires are amorphous and semiconducting and feature a controlled sp(2)/sp(3) ratio. The growth mechanism which is based on the catalyst nanoisland analysis by AFM and takes into account the hydrogenation and temperature control effects explains the observed switch-over of the nanostructure growth modes. These results are important to achieve the ultimate control of chirality, structure, and conductivity of one-dimensional all-carbon networks.
authors.affiliation: Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, Lindfield, New South Wales, 2070, Australia.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Han
authors.forename: S
authors.initials: S
authors.lastname: Yick
authors.forename: I
authors.initials: I
authors.lastname: Levchenko
authors.forename: E
authors.initials: E
authors.lastname: Tam
authors.forename: M M A
authors.initials: MM
authors.lastname: Yajadda
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: P J
authors.initials: PJ
authors.lastname: Martin
authors.forename: S
authors.initials: S
authors.lastname: Furman
authors.forename: K
authors.initials: K
authors.lastname: Ostrikov