Crystallization of carbon nanotubes in low temperature plasma

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:212950

Byszewski, P; Ukalski, K ^[1]; Huczko, A ^[2]

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1. Inst. of Vacuum Technology, Warsaw (Poland)
2. Warsaw Univ. (Poland); and others

The multishell carbon nanotubes consist of several concentric rolled graphene planes, each of them built of carbon hexagons arranged in helicoidally around the axis. The tubes can be grown in the DC arc plasma in He atmosphere, using either graphite or amorphous carbon electrodes (temperatures >3800K), or by decomposition of hydrocarbon compounds in carbon plasma electric field. Our experiments on nanotubes growth have been performed in the DC electric arc, where as the electrodes spectrally pure (6 mm diameter) graphite rods have been used. We have maintained the inter electrode gap at approx. 5mm, during the process, the anode heated by electrons evaporated and part of the carbon condensed on the cathode, we have tried to determine stable conditions of the process, when most of the evaporated material was transferred to the cathode (approx. 75%) and appropriate for tubes growth. For this purpose helium pressure was varied in the range 0.1 to 0.7 atm. and current from 90A to 70A respectively, i.e. increasing pressure required decreasing the current. The deposits have been investigated by means of x-ray and electron diffraction and high resolution transmission electron microscopy. They consisted of two regions of different morphology and crystalline structure: the outer hard part contained turbostratic graphite and the inner core bundles of nanotubes, graphene ribbons and multi layer macro fullerenes.

• OSTI ID: 212950
• Report Number(s): CONF-950749--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
66 PHYSICS
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