High-Temperature Resistivity of Dense Mats of Single-Walled Carbon Nanotube Bundles

• Published in: Journal of physical chemistry. C Vol. 115; no. 22; pp. 11023 - 11029
• Main Authors: Latini, Alessandro, Gozzi, Daniele, Ferraris, Giovanni, Lazzarini, Laura
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.06.2011
• Subjects: C: Nanops and Nanostructures
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp203149v

The resistivity of mats of single-walled carbon nanotube (SWCNT) bundles has been measured in the temperature range 286–1051 K under high vacuum. The apparent density of mats was close to 1 g cm–3 as obtained by pressing a weighted amount of SWCNTs at 0.6 GPa. Large hysteresis of resistivity has been recorded through thermal cycles at different temperature rate changes. At constant temperature, the mats display a perfect ohmic behavior. Notwithstanding the metallic behavior, the Bloch–Grüneisen equation is not fully respected, and it has been modified with the insert of a temperature-dependent term that accounts for changes inside and among the bundles. The coefficient of thermal resistivity has been found strongly dependent on temperature with a maximum at 566 K and crossing zero at 310 K. A simple model to explain the TCR behavior is given which is supported by the micropore size distribution and BJH isotherms.