Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical Properties
A bimetallic cobalt-iron catalyst was utilized to demonstrate the growth of multiwalled carbon nanotubes (CNTs) at low gas pressure through thermal chemical vapor deposition. The characteristics of multiwalled CNTs were investigated based on the effects of catalyst thickness and gas pressure variati...
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doaj-a73c77ffb78740768b764116b0f2f8382020-11-24T23:45:48ZengHindawi LimitedJournal of Nanomaterials1687-41101687-41292013-01-01201310.1155/2013/637939637939Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical PropertiesMuhammad Aniq Shazni Mohammad Haniff0Hing Wah Lee1Wai Yee Lee2Daniel C. S. Bien3Khairul Anuar Wahid4Mai Woon Lee5Ishak Abd. Azid6NEMS and Photonics Cluster, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, MalaysiaNEMS and Photonics Cluster, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, MalaysiaNEMS and Photonics Cluster, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, MalaysiaNEMS and Photonics Cluster, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, MalaysiaNEMS and Photonics Cluster, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, MalaysiaNEMS and Photonics Cluster, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, MalaysiaSchool of Mechanical Engineering, USM Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, MalaysiaA bimetallic cobalt-iron catalyst was utilized to demonstrate the growth of multiwalled carbon nanotubes (CNTs) at low gas pressure through thermal chemical vapor deposition. The characteristics of multiwalled CNTs were investigated based on the effects of catalyst thickness and gas pressure variation. The results revealed that the average diameter of nanotubes increased with increasing catalyst thickness, which can be correlated to the increase in particle size. The growth rate of the nanotubes also increased significantly by ~2.5 times with further increment of gas pressure from 0.5 Torr to 1.0 Torr. Rapid growth rate of nanotubes was observed at a catalyst thickness of 6 nm, but it decreased with the increase in catalyst thickness. The higher composition of 50% cobalt in the cobalt-iron catalyst showed improvement in the growth rate of nanotubes and the quality of nanotube structures compared with that of 20% cobalt. For the electrical properties, the measured sheet resistance decreased with the increase in the height of nanotubes because of higher growth rate. This behavior is likely due to the larger contact area of nanotubes, which improved electron hopping from one localized tube to another.http://dx.doi.org/10.1155/2013/637939 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Muhammad Aniq Shazni Mohammad Haniff Hing Wah Lee Wai Yee Lee Daniel C. S. Bien Khairul Anuar Wahid Mai Woon Lee Ishak Abd. Azid |
spellingShingle |
Muhammad Aniq Shazni Mohammad Haniff Hing Wah Lee Wai Yee Lee Daniel C. S. Bien Khairul Anuar Wahid Mai Woon Lee Ishak Abd. Azid Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical Properties Journal of Nanomaterials |
author_facet |
Muhammad Aniq Shazni Mohammad Haniff Hing Wah Lee Wai Yee Lee Daniel C. S. Bien Khairul Anuar Wahid Mai Woon Lee Ishak Abd. Azid |
author_sort |
Muhammad Aniq Shazni Mohammad Haniff |
title |
Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical Properties |
title_short |
Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical Properties |
title_full |
Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical Properties |
title_fullStr |
Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical Properties |
title_full_unstemmed |
Investigation of Low-Pressure Bimetallic Cobalt-Iron Catalyst-Grown Multiwalled Carbon Nanotubes and Their Electrical Properties |
title_sort |
investigation of low-pressure bimetallic cobalt-iron catalyst-grown multiwalled carbon nanotubes and their electrical properties |
publisher |
Hindawi Limited |
series |
Journal of Nanomaterials |
issn |
1687-4110 1687-4129 |
publishDate |
2013-01-01 |
description |
A bimetallic cobalt-iron catalyst was utilized to demonstrate the growth of multiwalled carbon nanotubes (CNTs) at low gas pressure through thermal chemical vapor deposition. The characteristics of multiwalled CNTs were investigated based on the effects of catalyst thickness and gas pressure variation. The results revealed that the average diameter of nanotubes increased with increasing catalyst thickness, which can be correlated to the increase in particle size. The growth rate of the nanotubes also increased significantly by ~2.5 times with further increment of gas pressure from 0.5 Torr to 1.0 Torr. Rapid growth rate of nanotubes was observed at a catalyst thickness of 6 nm, but it decreased with the increase in catalyst thickness. The higher composition of 50% cobalt in the cobalt-iron catalyst showed improvement in the growth rate of nanotubes and the quality of nanotube structures compared with that of 20% cobalt. For the electrical properties, the measured sheet resistance decreased with the increase in the height of nanotubes because of higher growth rate. This behavior is likely due to the larger contact area of nanotubes, which improved electron hopping from one localized tube to another. |
url |
http://dx.doi.org/10.1155/2013/637939 |
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