Metal catalyst in CVD growth of carbon nanotubes: role of chemical composition

2010 ◽  
Author(s):  
Oleg V. Yazyev ◽  
Alfredo Pasquarello ◽  
Marília Caldas ◽  
Nelson Studart
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Composition ◽  
Metal Catalyst ◽  
Cvd Growth

Vapor-Phase Catalyst Delivery Method for Growing SiC Nanowires

2013 ◽  
Vol 740-742 ◽  
pp. 209-212 ◽  
Author(s):  
Rooban Venkatesh K.G. Thirumalai ◽  
Bharat Krishnan ◽  
Albert Davydov ◽  
Joseph Neil Merrett ◽  
Yaroslav Koshka
Keyword(s):  
Vapor Phase ◽  
Gas Flow ◽  
Substrate Surface ◽  
Metal Catalyst ◽  
Catalyst Nanoparticles ◽  
Sic Nanowires ◽  
Cvd Growth ◽  
Hot Zone

A method was developed for growing SiC nanowires without depositing a metal catalyst on the targeted surfaces prior to the CVD growth. The proposed method utilizes in-situ vapor-phase catalyst delivery via sublimation of the catalyst from a metal source placed in the hot zone of the CVD reactor, followed by condensation of the catalyst-rich vapor on the bare substrate surface to form the catalyst nanoparticles. The vapor-phase catalyst delivery and the resulting nanowire density was found to be influenced by both the gas flow rate and the catalyst diffusion through the boundary layer above the catalyst source. The origin of undesirable bushes of nanowires and the role of the C/Si ratio were established.

scholarly journals Growth mechanisms of single-wall carbon nanotubes in a chemical vapor deposition (CVD) process on Fe/Mo-Al catalyst

2013 ◽  
Vol 16 (1) ◽  
pp. 72-80
Author(s):  
Thang Van Le
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Wall Carbon Nanotubes ◽  
Metal Catalyst ◽  
Formation Mechanisms ◽  
Growth Mechanisms ◽  
Cvd Growth ◽  
Walled Carbon Nanotubes

The formation mechanisms involved in the growth of single-walled carbon nanotubes (SWNTs) by chemical vapor deposition (CVD) was studied. Transmission electron microscopy (TEM) was used to analyze the encapsulated metal catalyst particles found within the tubes, and the dimensions and location of these particles was determined. SWNTs were found to have encapsulated particles in the end of tubes, with large length to diameter ratios. As a result of these observations, we concluded that SWNTs are formed via an open-ended, base-growth mechanism (VLS mechanism). Additionally, we have demonstrated the formation of two kinds of bundles of SWNTs (Parallel bundles and as-rope bundles). SWNTs grown with thermal CVD on Fe/Mo-Al catalyst did not contain similar elongated particles or particles along the middle of the tubes, indicating that these new growth mechanisms are only applicable in the case of tubes grown via vapor phase CVD growth methods.

EFFECT OF THE TEMPERATURE AND CATALYST LAYER OF MO/FE/AL ON GROWTH OF CARBON NANOTUBES

2010 ◽  
Vol 13 (3) ◽  
pp. 19-28
Author(s):  
Anh Tuan Nguyen ◽  
Hai Duy Dinh ◽  
Chien Mau Dang ◽  
Wooseok Song ◽  
Seong Kyu Kim ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor ◽  
Catalyst Layer ◽  
Effect Of Temperature ◽  
Metal Catalyst ◽  
Chemical Vapor Deposition Method ◽  
Dc Sputtering ◽  
Metal Layers

Carbon nanotubes (CNTs) were synthesized by thermal chemical vapor deposition method using a three layer Mo-Fe-Al metal catalyst. All metal layers were deposited by DC sputtering method. By analysis with SEM and Raman spectra, we investigated the effect of temperature and the role of Mo layer on the quality of synthesis CNTs.

Mechanisms for Catalytic CVD Growth of Multiwalled Carbon Nanotubes

2008 ◽  
Vol 8 (11) ◽  
pp. 6054-6064 ◽  
Author(s):  
Navdeep Bajwa ◽  
Xuesong Li ◽  
Pulickel M. Ajayan ◽  
Robert Vajtai
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Review Paper ◽  
Chemical Vapor ◽  
Multiwalled Carbon ◽  
Chemical Vapor Deposition Growth ◽  
Complete Knowledge ◽  
Cvd Growth ◽  
Nanotube Growth

Carbon nanotubes possess unique properties that make them potentially ideal materials for various technological applications. However, a basic growth mechanism explaining the way metallic atoms interact with carbon to nucleate, grow and heal CNTs still needs to be understood. In this review paper we describe the mechanisms of catalytic chemical vapor deposition growth of multiwalled carbon nanotubes and carbon nanofibers, the role of various parameters that govern their growth kinetics and the knowledge added to singlewalled nanotube growth. We also examine future strategies needed to reveal complete knowledge of the growth mechanisms of carbon nanotubes.

Fabrication of Carbon Nanotube Triode Using Helicon Plasma Cvd with Electroplated Nico Catalyst

2003 ◽  
Vol 772 ◽  
Author(s):  
Masakazu Muroyama ◽  
Kazuto Kimura ◽  
Takao Yagi ◽  
Ichiro Saito
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Metal Catalyst ◽  
Ni Catalyst ◽  
Plasma Cvd ◽  
Helicon Plasma ◽  
Plasma Enhanced Cvd ◽  
Turn On ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned

AbstractA carbon nanotube triode using Helicon Plasma-enhanced CVD with electroplated NiCo catalyst has been successfully fabricated. Isolated NiCo based metal catalyst was deposited at the bottom of the cathode wells by electroplating methods to control the density of carbon nanotubes and also reduce the activation energy of its growth. Helicon Plasma-enhanced CVD (HPECVD) has been used to deposit nanotubes at 400°C. Vertically aligned carbon nanotubes were then grown selectively on the electroplated Ni catalyst. Field emission measurements were performed with a triode structure. At a cathode to anode gap of 1.1mm, the turn on voltage for the gate was 170V.

scholarly journals The role of carbon nanotubes on the sensitivity of composites with polyaniline for ammonia sensors

Carbon Trends ◽  
2021 ◽  
Vol 3 ◽  
pp. 100026
Author(s):  
Marcelo Eising ◽  
Colin O'Callaghan ◽  
Carlos Eduardo Cava ◽  
Ariane Schmidt ◽  
Aldo José Gorgatti Zarbin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Ammonia Sensors
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