Introducing thermally stable inter-tube defects to assist off-axial phonon transport in carbon nanotube films
- Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States)
- Department of Nuclear Engineering, Texas A and M University, College Station, Texas, 77843 (United States)
Through integrated molecular dynamics (MD) simulations and experimental studies, we demonstrated the feasibility of an ion-irradiation-and-annealing based phonon engineering technique to enhance thermal conductivity of carbon nanotube (CNT) films. Upon ion irradiation of CNT films, both inter-tube defects and intra-tube defects are introduced. Our MD simulations show that inter-tube defects created between neighboring tubes are much more stable than intra-tube defects created on tube graphitic planes. Upon thermal annealing, intra-tube defects are preferentially removed but inter-tube defects stay. Consequently, axial phonon transport increases due to reduced phonon scattering and off-axial phonon transport is sustained due to the high stability of inter-tube defects, leading to a conductivity enhancement upon annealing. The modeling predictions agree with experimental observations that thermal conductivities of CNT films were enhanced after 2 MeV hydrogen ion irradiations and conductivities were further enhanced upon post irradiation annealing.
- OSTI ID:
- 22273414
- Journal Information:
- Applied Physics Letters, Vol. 104, Issue 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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