Direct observation of heat dissipation in individual suspended carbon nanotubes using a two-laser technique

Autor:	Stephen B. Cronin, Chia-Chi Chang, Mehmet Aykol, Wei Hsuan Hung, Michael T. Pettes, Li Shi, I. Kai Hsu, Jesse Theiss
Rok vydání:	2011
Předmět:	Nanotube Materials science General Physics and Astronomy Nanotechnology Carbon nanotube Molecular physics law.invention Condensed Matter::Materials Science symbols.namesake Raman laser Thermal conductivity law Bundle Heat transfer symbols Raman spectroscopy Temperature coefficient
Zdroj:	Journal of Applied Physics. 110:044328
ISSN:	1089-7550 0021-8979
Popis:	A two-laser technique is used to investigate heat spreading along individual single walled carbon nanotube (SWCNT) bundles in vacuum and air environments. A 532 nm laser focused on the center of a suspended SWCNT bundle is used as a local heat source, and a 633 nm laser is used to measure the spatial temperature profile along the SWCNT bundle by monitoring the G band downshifts in the Raman spectra. A constant temperature gradient is observed when the SWCNT bundle is irradiated in vacuum, giving direct evidence of diffusive transport of the phonons probed by the Raman laser. In air, however, we observe an exponentially decaying temperature profile with a decay length of about 7 μm, due to heat dissipation from the SWCNT bundle to the surrounding gas molecules. The thermal conductivity of the suspended carbon nanotube (CNT) is determined from its electrical heating temperature profile as measured in vacuum and the nanotube bundle diameter measured via transmission electron microscopy. Based on the exponent...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::59ce7163c6c8b19de56c1853beaa12d2 https://doi.org/10.1063/1.3627236 Zobrazit plný text záznamu