title: Mechanism of the initial stages of nitrogen-doped single-walled carbon nanotube growth.
abstract: We have studied the mechanism of the initial stages of nitrogen-doped single-walled carbon nanotube growth illustrated for the case of a floating catalyst chemical vapor deposition system, which uses carbon monoxide (CO) and ammonia (NH(3)) as precursors and iron as a catalyst. We performed first-principles electronic-structure calculations, fully incorporating the effects of spin polarization and magnetic moments, to investigate the bonding and chemistry of CO, NH(3), and their fragments on a model Fe(55) icosahedral cluster. A possible dissociation path for NH(3) to atomic nitrogen and hydrogen was identified, with a reaction barrier consistent with an experimentally determined value we measured by tandem infrared and mass spectrometry. Both C-C and C-N bond formation reactions were found to be barrierless and exothermic, while a parasitic reaction of HCN formation had a barrier of over 1 eV.
authors.affiliation: Department of Applied Physics, Aalto University School of Science, Aalto, Espoo, Finland. toma.susi@tkk.fi
authors.forename: Toma
authors.initials: T
authors.lastname: Susi
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lanzani
authors.forename: Albert G
authors.initials: AG
authors.lastname: Nasibulin
authors.forename: Paola
authors.initials: P
authors.lastname: Ayala
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Thomas
authors.initials: T
authors.lastname: Bligaard
authors.forename: Kari
authors.initials: K
authors.lastname: Laasonen
authors.forename: Esko I
authors.initials: EI
authors.lastname: Kauppinen