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

Nature Materials volume 16, pages 892897 (2017) | Download Citation


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 20021,2. 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.

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We thank M. Barako for advice on writing the manuscript; M. Asheghi, J. Cho, J. Li, A. Marconnet, S. Roy and A. Sood for discussions on thermal and thermoelectric measurements; and H. Ishiwata for support on Raman spectroscopic measurement. The experimental part of this work was financially supported by the Air Force Office of Scientific Research (AFOSR, no. FA9550-12-1-0195), the National Science Foundation (NSF, no. 1336734), and JSPS KAKENHI (no. JP16H06722). The theory part was financially supported by JST-CREST (no. JPMJCR16Q5) and JSPS KAKENHI (no. JP16H04274).

Author information


  1. Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA

    • Takashi Kodama
    • , Woosung Park
    •  & Kenneth E. Goodson
  2. Department of Mechanical Engineering, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan

    • Masato Ohnishi
    • , Takuma Shiga
    •  & Junichiro Shiomi
  3. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA

    • Joonsuk Park
  4. Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan

    • Takashi Shimada
  5. Department of Chemistry, Nagoya University, Nagoya 464-8602, Japan

    • Hisanori Shinohara


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T.K. led the project and contributed to the experimental works including device design, fabrication, and conduction measurement. M.O., T.Shiga and J.S. contributed to the theoretical work. W.P. contributed to the SEM imaging and conduction measurement. J.P. contributed to the TEM imaging. T.Shimada and H.S. synthesized and provided all of the CNT samples used in the project. K.E.G. served both as PI and primary advisor for the thermal and thermoelectric measurements. T.K., M.O., T.Shiga, J.S. and K.E.G. wrote the paper.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Takashi Kodama or Kenneth E. Goodson.

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