Aligned Carbon Nanotubes Via Microwave Plasma Enhanced Chemical Vapor Deposition

1999 ◽  
Vol 593 ◽  
Author(s):  
H. Cui ◽  
D. Palmer ◽  
O. Zhou ◽  
B. R. Stoner

ABSTRACTAligned multi-wall carbon nanotubes have been grown on silicon substrates by microwave plasma enhanced chemical vapor deposition using methane/ammonia mixtures. The concentration ratio of methane/ammonia in addition to substrate temperature was varied. The morphology, structure and alignment of carbon nanotubes were studied by scanning electron microscopy and transmission electron microscopy. Both concentric hollow and bamboo-type multi-wall carbon nanotubes were observed. Growth rate, size distribution, alignment, morphology, and structure of carbon nanotubes changed with methane/ammonia ratio and growth temperature. Preliminary results on field emission properties are also presented.

2003 ◽  
Vol 788 ◽  
Author(s):  
K. G. Belay ◽  
J Jackson ◽  
Yan Xin

ABSTRACTBoth carbon nanotubes and carbon nanofibers were grown on a thick nickel substrate by means of microwave plasma enhanced chemical vapor deposition (MPECVD) process using 20% CH4 and 80% H2 at a temperature of 750°C and a pressure of 50 Torr. The substrate was pre-abraded with 1.0μm diamond powder and 15.0 μm diamond paste to increase the rate of nucleation. When the substrate is taken out of the reactor the film detaches itself completely from the nickel. Unusual outgrowth structures appear jutted on one section of the substrate in a symmetrical manner. These structures were very hard and, when analyzed using environmental scanning electron microscope (ESEM), Raman microscopy and transmission electron microscope (TEM), micro-trees and an abundance of multi wall carbon nanotubes (MWCNTs) and nanofibers were observed. An attempt to measure the hardness of the film using a nano-indenter was inconclusive due to the extreme hardness of the material produced.


2016 ◽  
Vol 4 (21) ◽  
pp. 4778-4785 ◽  
Author(s):  
Wen Yuan ◽  
Liping Fang ◽  
Zhen Feng ◽  
Zexiang Chen ◽  
Jianwu Wen ◽  
...  

In this study, triethylamine (TEA) dissolved in the methanol was used as a liquid nitrogen source to synthesize nitrogen-doped ultrananocrystalline diamond (N-UNCD) films on silicon substrates via microwave plasma enhanced chemical vapor deposition (MPCVD).


2000 ◽  
Vol 621 ◽  
Author(s):  
Y.S. Woo ◽  
I.T. Han ◽  
N.S. Lee ◽  
J.E. Jung ◽  
D.Y. Jeon ◽  
...  

ABSTRACTSynthesis of multi-wall carbon nanotubes (MWNTs) was attempted by microwave plasma enhanced chemical vapor deposition using CH4/H2/NH3 gases on Ni/Cr-coated glass at low temperature. The synthesis was investigated by optical emission spectroscopy and quadrupole mass spectroscopy. It was observed that MWNTs could be grown within a very restrictive range of gas compositions. An addition of a small amount of NH3 resulted in a decrease of C2H2, which can be used to estimate the amount of carbon sources in plasma for the growth of MWNTs, and an increase of CN and Hα radicals acting as etching species of carbon phases. These results show that carbon nanotubes can be grown only under an appropriate condition that the growing process surpasses the etching process. The optimum C2H2 /Hα ratio in a gas mixture was found to be between 1 and 3 for the MWNT growth at low temperature.


2007 ◽  
Vol 7 (12) ◽  
pp. 4272-4277 ◽  
Author(s):  
Rakesh K. Joshi ◽  
Masamishi Yoshimura ◽  
Yusuke Matsuura ◽  
Kazuyuki Ueda ◽  
Kei Tanaka

Pd nanoparticles of well-defined shapes with face centered cubic structure were grown electrochemically on silicon substrates with high degree of reproducibility. As direct application of these electrochemically grown Pd nanostructures they have been used as catalyst for the growth of multi wall carbon nanotube (MWCNT). It is observed that the MWCNTs are filled with a Pd based material during growth by microwave plasma enhanced chemical vapor deposition (MPECVD) technique. High-resolution transmission electron microscopy, used to study the material inside MWCNT suggests the formation of PdH0 649 or Pd2 Si during the growth of carbon nanotube. Raman spectroscopy has been used to study the structure of the MPECVD grown carbon nanotubes.


2005 ◽  
Author(s):  
Kinghong Kwok ◽  
Wilson K. S. Chiu

Carbon nanotubes have unique mechanical, electronic and thermal properties with applications ranging from reinforced composite materials to micro-scale electronic devices, and are considered one of the next generation advanced engineering materials. In this study, a laser-induced chemical vapor deposition (LCVD) process has been developed that is capable of depositing carbon nanotubes in open-air from a gas mixture consisting of propane and hydrogen. A CO2 laser is used to irradiate the substrate covered with metal nanoparticles, subsequently resulting in the growth of multi-wall carbon nanotubes. The effect of laser power and reactant gas flow configuration on carbon nanotube growth kinetics is experimentally investigated. Results indicate that carbon nanotube synthesis is highly dependent on the laser-induced temperature distribution and the carbon radical concentration. Transmission electron microscopy, scanning electron microscopy and Raman spectroscopy are used to relate the composition, microstructure and growth kinetics to the process conditions of carbon nanotubes deposited in this study.


2005 ◽  
Vol 20 (3) ◽  
pp. 703-711 ◽  
Author(s):  
Hou-Guang Chen ◽  
Li Chang

We report a unique morphology of diamond nanoplatelets synthesized by microwave plasma chemical vapor deposition on Ni coated polycrystalline diamond substrates. The diamond nanoplatelets were as thin as approximately 30 nm. Electron microscopy showed that the diamond nanoplatelets appear in a shape consisting of trapezoid and parallelogram tabular crystallites. Furthermore, the diamond nanoplatelets were single crystalline, as shown by electron diffraction. The edges of nanoplatelets were along the 〈110〉 direction with both the top and bottom tabular surfaces parallel to the {111} plane. Transmission electron microscopy revealed that the twinned planes are parallel to the platelet and side-face structure in ridge shape is bounded by {100} and {111} planes. Lateral growth of diamond nanoplatelet is believed to result from twin and ridge face structure. An oriented thin graphite layer was observed on some diamond nanoplatelets.


2007 ◽  
Vol 121-123 ◽  
pp. 101-104
Author(s):  
Xiao Ping Zou ◽  
H. Abe ◽  
Toru Shimizu ◽  
A. Ando ◽  
H. Tokumoto ◽  
...  

A simple thermal chemical vapor deposition (STCVD) growth technique of multi-walled carbon nanotubes (MWCNTs) is present. Carbon nanotube film was synthesized on the Pt plate substrates by pyrolysis of ethyl alcohol as carbon source at lower reaction temperature at atmospheric pressure by using simple apparatus. The as-synthesized MWCNTs were characterized by both scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The electrical property of an individual MWCNT was evaluated by I-V measurement. The electrical resistance of single MWCNT is about 450 k/ in linear region under bias voltage between 2 to 4 V. It can undergo a large current of 6 2A at 4 V


Author(s):  
K. Doong ◽  
J.-M. Fu ◽  
Y.-C. Huang

Abstract The specimen preparation technique using focused ion beam (FIB) to generate cross-sectional transmission electron microscopy (XTEM) samples of chemical vapor deposition (CVD) of Tungsten-plug (W-plug) and Tungsten Silicides (WSix) was studied. Using the combination method including two axes tilting[l], gas enhanced focused ion beam milling[2] and sacrificial metal coating on both sides of electron transmission membrane[3], it was possible to prepare a sample with minimal thickness (less than 1000 A) to get high spatial resolution in TEM observation. Based on this novel thinning technique, some applications such as XTEM observation of W-plug with different aspect ratio (I - 6), and the grain structure of CVD W-plug and CVD WSix were done. Also the problems and artifacts of XTEM sample preparation of high Z-factor material such as CVD W-plug and CVD WSix were given and the ways to avoid or minimize them were suggested.


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