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Methane chemical vapor deposition on transition metal/GaAs samples – a possible route to Haeckelite carbon nanotubes?
Author(s) -
Burek Michael J.,
Hesjedal Thorsten
Publication year - 2012
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3827
Subject(s) - carbon nanotube , chemical vapor deposition , raman spectroscopy , methane , transition metal , carbon fibers , semiconductor , metal , materials science , chemical engineering , analytical chemistry (journal) , deposition (geology) , nanotechnology , chemistry , optoelectronics , organic chemistry , composite material , metallurgy , catalysis , optics , paleontology , physics , engineering , sediment , composite number , biology
We present a systematic study of atmospheric chemical vapor deposition growth of carbon nanotubes (CNTs) on patterned, transition metal/GaAs samples employing methane as the carbon feedstock. Controlled CNT growth was found to occur from the exposed metal‐semiconductor interface, rather than from the metal or semiconductor surfaces themselves. A fast sample loading system allowed for a minimization of the exposure to high temperatures, thereby preventing excessive sample damage. The optimum growth temperature for CrNi/GaAs interfaces is 700 °C (at a methane flow rate of 700 sccm). Possible growth scenarios involving the Ni–As–Ga system and its interaction with C is discussed. Raman spectroscopy of the CNTs revealed the presence of pentagon–heptagon defects. Closer analysis of the spectra points towards a mixture of so‐called Haeckelite CNTs. Copyright © 2011 John Wiley & Sons, Ltd.