Modulation of thermal and thermoelectric transport in individual carbon nanotubes by fullerene encapsulation

• Published in: Nature materials Vol. 16; no. 9; pp. 892 - 897
• Main Authors: Kodama, Takashi, Ohnishi, Masato, Park, Woosung, Shiga, Takuma, Park, Joonsuk, Shimada, Takashi, Shinohara, Hisanori, Shiomi, Junichiro, Goodson, Kenneth E.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2017; Nature Publishing Group
• Subjects: 140/133; 142/126; 639/166/988; 639/925/357/73; 639/925/927/359; Biomaterials; Carbon; Carbon nanotubes; Condensed Matter Physics; Electrical properties; Electrical resistivity; Encapsulation; Fullerenes; letter; Low temperature; Materials Science; Modulation; Nanofabrication; Nanotechnology; Nanotubes; Optical and Electronic Materials; Temperature dependence; Temperature measurement; Thermal conductivity; Thermal energy; Thermal properties; Thermodynamic properties; Transport
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat4946

Encapsulation of single- and double-wall carbon nanotubes in carbon nanocages, which may contain gadolinium or erbium, leads to a reduction of the thermal conductivity and an improved Seebeck coefficient. The potential impact of encapsulated molecules on the thermal properties of individual carbon nanotubes (CNTs) has been an important open question since the first reports of the strong modulation of electrical properties in 2002 1 , 2 . However, thermal property modulation has not been demonstrated experimentally because of the difficulty of realizing CNT-encapsulated molecules as part of thermal transport microstructures. Here we develop a nanofabrication strategy that enables measurement of the impact of encapsulation on the thermal conductivity ( κ ) and thermopower ( S ) of single CNT bundles that encapsulate C 60 , Gd@C 82 and Er 2 @C 82 . Encapsulation causes 35–55% suppression in κ and approximately 40% enhancement in S compared with the properties of hollow CNTs at room temperature. Measurements of temperature dependence from 40 to 320 K demonstrate a shift of the peak in the κ to lower temperature. The data are consistent with simulations accounting for the interaction between CNTs and encapsulated fullerenes.