title: Extracting subnanometer single shells from ultralong multiwalled carbon nanotubes.
abstract: We report a simple but powerful method for engineering multi-walled carbon nanotubes (MWNTs) by using manipulation by an atomic-force microscope. The successive shell-by-shell extraction process of ultralong MWNTs allows the exposure of the innermost single-walled carbon nanotubes (SWNTs), which have diameters as small as approximately 0.4 nm. The inner-shell extraction process changes the electrical characteristics of the MWNTs. Whereas the outer hollowed-out nanotubes show either metallic or semiconducting character, the innermost SWNTs of small diameter exhibit predominantly metallic transport properties.
authors.affiliation: Nanoscale Science and Engineering Center, Columbia University, New York, NY 10027, USA.
authors.forename: Byung Hee
authors.initials: BH
authors.lastname: Hong
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Small
authors.forename: Meninder S
authors.initials: MS
authors.lastname: Purewal
authors.forename: Asher
authors.initials: A
authors.lastname: Mullokandov
authors.forename: Matthew Y
authors.initials: MY
authors.lastname: Sfeir
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Ju Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Tony F
authors.initials: TF
authors.lastname: Heinz
authors.forename: Louis E
authors.initials: LE
authors.lastname: Brus
authors.forename: Philip
authors.initials: P
authors.lastname: Kim
authors.forename: Kwang S
authors.initials: KS
authors.lastname: Kim