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Thermal property tuning in aligned carbon nanotube films and random entangled carbon nanotube films by ion irradiation.
- Source :
-
Applied Physics Letters . 10/12/2015, Vol. 107 Issue 15, p1-5. 5p. 2 Diagrams, 4 Graphs. - Publication Year :
- 2015
-
Abstract
- Ion irradiation effects on thermal property changes are compared between aligned carbon nanotube (A-CNT) films and randomly entangled carbon nanotube (R-CNT) films. After H, C, and Fe ion irradiation, a focusing ion beam with sub-mm diameter is used as a heating source, and an infrared signal is recorded to extract thermal conductivity. Ion irradiation decreases thermal conductivity of A-CNT films, but increases that of R-CNT films. We explain the opposite trends by the fact that neighboring CNT bundles are loosely bonded in A-CNT films, which makes it difficult to create inter-tube linkage/bonding upon ion irradiation. In a comparison, in R-CNT films, which have dense tube networking, carbon displacements are easily trapped between touching tubes and act as intertube linkage to promote off-axial phonon transport. The enhancement overcomes the phonon transport loss due to phonon-defect scattering along the axial direction. A model is established to explain the dependence of thermal conductivity changes on ion irradiation parameters including ion species, energies, and current. [ABSTRACT FROM AUTHOR]
- Subjects :
- *THERMAL properties
*CARBON nanotubes
*NANOFILMS
*THERMAL conductivity
*IRRADIATION
Subjects
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 107
- Issue :
- 15
- Database :
- Academic Search Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 110422614
- Full Text :
- https://doi.org/10.1063/1.4931683