Stephan Hofmann,
Renu Sharma,
Caterina Ducati,
Gaohui Du,
Cecilia Mattevi,
Cinzia Cepek,
Mirco Cantoro,
Simone Pisana,
Atlus Parvez,
Felipe Cervantes-Sodi,
Andrea C Ferrari, Rafal Dunin-Borkowski,
Silvano Lizzit,
Luca Petaccia,
Andrea Goldoni,
John Robertson
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ABSTRACT: We present atomic-scale, video-rate environmental transmission electron microscopy and in situ time-resolved X-ray photoelectron spectroscopy of surface-bound catalytic chemical vapor deposition of single-walled carbon nanotubes and nanofibers. We observe that transition metal catalyst nanoparticles on SiOx support show crystalline lattice fringe contrast and high deformability before and during nanotube formation. A single-walled carbon nanotube nucleates by lift-off of a carbon cap. Cap stabilization and nanotube growth involve the dynamic reshaping of the catalyst nanocrystal itself. For a carbon nanofiber, the graphene layer stacking is determined by the successive elongation and contraction of the catalyst nanoparticle at its tip.
Nano Letters 04/2007; 7(3):602-8. · 13.20 Impact Factor
