Transmission electron microscopy and electrical transport investigations performed on the same single-walled carbon nanotube

1998 ◽  
Author(s):  
G. Philipp ◽  
M. Burghard ◽  
S. Roth
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Nanotube ◽  
Electrical Transport ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Transmission Electron

Compound growth and microstructure of carbon nanotube

2003 ◽  
Vol 18 (10) ◽  
pp. 2459-2463 ◽  
Author(s):  
Zaoli Zhang ◽  
Lian Ouyang ◽  
Zujin Shi ◽  
Zhennan Gu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Nanotube ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Multiwalled Carbon ◽  
Catalyst Nanoparticles ◽  
Single Walled Carbon Nanotube ◽  
Fe Catalyst ◽  
Transmission Electron

The compound growth of single-walled carbon nanotube (SWCNT) and multiwalled carbon nanotube (MWCNT), which formed a nanotube cable, was achieved by the chemical vapor deposition of natural gas on an Fe catalyst supported on SiO2–Al2O3 hybrid materials at 950 °C. The microstructure of nanotubes was characterized by high-resolution transmission electron microscopy (HRTEM). The SWCNTs encapsulated inside MWCNTs can be two, three, or even more in quantity with a diameter range from 1.0 nm to 2.0 nm. The diameter of SWCNT is controlled by the size of the catalyst nanoparticles. Some bundles of SWCNT and double-walled nanotubes were also found. The possible mechanism of compound growth is briefly discussed.

Characteristics of Gas Sensors Based on Single-Walled Carbon Nanotube Bundles Treated by Acid Stirring

2007 ◽  
Vol 124-126 ◽  
pp. 1173-1176
Author(s):  
Hong Quang Nguyen ◽  
Shao Lin Zhang ◽  
Gi Hong Rue ◽  
Jeung Soo Huh
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotube ◽  
Gas Sensors ◽  
Acid Treatment ◽  
Room Temperature ◽  
Sem Images ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Gas Molecules

The paper presents the effect of acid treatment on the structure of single-walled carbon nanotube (SWNT) bundles and on the characteristics of SWNT-based gas sensors. The commercial SWNT powder was treated with a mixture of concentrated H2SO4:HNO3 (3:1 in volume) before used to fabricate sensors for ammonia (NH3) detection at room temperature. The Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) images indicated that the acid treatment not only removed most of catalytic particles from the SWNT bundles, but also caused SWNT bundles to be fragile. The fracture of the SWNT facilitated for gas molecules to adsorb in the SWNT sites, leading to an enhancement in sensitivity of the sensors. Upon exposing to 50 ppm NH3 in 450 sccm of nitrogen flowing rate at room temperature, the resistance of the 2-h-stirred sensors increased to 38% compared to 22% of the 1-h-stirred sensor. The recovery of the SWNT sensor was also accelerated owing to the treatment. These findings opened a new direction to improve the characteristics of SWNT-based gas sensors.

ELECTRICAL TRANSPORT PROPERTIES OF SINGLE-WALLED CARBON NANOTUBE BUNDLES TREATED WITH BORIC ACID

NANO ◽  
2011 ◽  
Vol 06 (04) ◽  
pp. 337-341 ◽  
Author(s):  
DALE HITCHCOCK ◽  
KEQIN YANG ◽  
JIAN HE ◽  
APPARAO M. RAO
Keyword(s):  
Carbon Nanotube ◽  
Boric Acid ◽  
Electrical Transport ◽  
Electrical Transport Properties ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Plasma Sintering ◽  
Treated Sample ◽  
Spark Plasma ◽  
Nonmonotonic Variation

Electric-arc-synthesized single-walled carbon nanotube (SWNT) bundles were sonicated in boric acid, dried and sintered under vacuum at 1200°C using a spark plasma sintering process. The nominal boric acid concentrations were 0%, 2.5%, 5%, 7.5%, 12.5% and 15%. This resulted in a nonmonotonic variation of carrier concentration in the resulting samples. The 7.5% boric acid treated sample showed the least magnitude and weakest temperature-dependence for the thermopower with a distinct phonon-drag peak that was absent in the other samples. These results are discussed within the framework of the doping-induced shift of the Fermi level and changes in the electron–phonon coupling.

Thermal and Electrical Transport Measurements of Single-Walled Carbon Nanotube Strands

2003 ◽  
Vol 788 ◽  
Author(s):  
Diana-Andra Borca-Tasciuc ◽  
Yann LeBon ◽  
Claire Nanot ◽  
Gang Chen ◽  
Theodorian Borca-Tasciuc ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotube ◽  
Electrical Properties ◽  
Specific Heat ◽  
Electrical Transport ◽  
Published Data ◽  
Temperature Dependent ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Temperature Dependent Properties

ABSTRACTThis work reports temperature dependent thermal and electrical properties characterization of long (mm size) single-walled carbon nanotube strands. Electrical properties are measured using a 4-probe method. Thermal conductivity and specific heat capacity are determined using an AC driven, self-heating method. Normalized values of resistivity, thermal conductivity, specific heat, thermal diffusivity, and the temperature coefficient of resistance are reported. The trends observed in the temperature dependent properties are comparable with previously published data on multi-walled carbon nanotube strands measured with a similar technique.

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