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Eur. Phys. J. Appl. Phys. 42, 247-250 (2008)
DOI: 10.1051/epjap:2008060
Influence of Fe/Cr on nitrogen doped carbon nanotube growth
C.P. Ewels1, 2, A. Gloter2, T. Minea3, B. Bouchet-Fabre4, S. Point1 and C. Colliex21 IMN, UMR6502 CNRS-Université de Nantes, 2 rue de la Houssinière, BP 32229, 44322 Nantes, France
2 LPS, UMR8502 CNRS-Université Paris Sud, bâtiment 510, 91405 Orsay, France
3 LPGP, UMR 8578 CNRS-Université Paris Sud, bâtiment 210, 91405 Orsay, France
4 LFP, CEA/DSM/DRECAM/SPAM - CNRS URA 2453, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
chris.ewels@cnrs-imn.fr
Received: 4 January 2008 / Received in final form: 6 March 2008 / Accepted: 6 March 2008 / Published online: 30 April 2008
Abstract
Using electron energy loss spectroscopy in a 100 kV VG
scanning transmission electron microscope we study nitrogen doped carbon
nanotubes grown via electron cyclotron resonance (ECR) microwave plasma
techniques. The process is controlled by direct current (dc) biasing the
grid separating the ECR source and the substrate. We show that plasma
induced sputtering of the ECR source wall (stainless steel) can lead to
significant iron and chromium contamination of growth samples. We identify
various Fe, Cr, Ni nitride phases, and propose a growth model based on
nitridation-induced metal segregation of steel based FeCrN alloys. Trace Cr
doping of nanotube catalysts appears a promising route for introducing large
nitrogen concentrations into both single and multi-walled nanotubes and may
accelerate nanotube growth rates.
81.10.Bk - Growth from vapor.
81.07.De - Nanotubes.
52.50.Sw - Plasma heating by microwaves; ECR, LH, collisional heating.
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