Dual catalytic purpose of the tungsten filament during the synthesis of single-helix carbon microcoils by hot-wire CVD.
We report on the deposition of crystalline single-helix carbon microcoils, in the as-deposited state, by the hot-wire chemical vapor deposition process without any special preparation of nano-sized transition metal catalysts and subsequent post-deposition annealing. Tungsten, originating from the heated tungsten filament, is identified as the catalyst material responsible for the growth of the microcoils. High-resolution transmission spectroscopy, combined with Raman spectroscopy, confirm that the as-deposited microcoils are crystalline, which is induced by the high deposition temperature in the vicinity of the heated filament. These results suggest a simplified, less tedious deposition process for the growth of carbon microcoils, once the process has been optimized.
Oliphant
C J
CJ
National Centre for Nano-Structured Materials, CSIR Materials Science and Manufacturing, PO Box 395, Pretoria 0001, South Africa.
Arendse
C J
CJ
Malgas
G F
GF
Motaung
D E
DE
Muller
T F G
TF
Knoesen
D
D