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-Gruneisen 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.
High temperature resistivity of dense mats of SWCNT bundles / Latini, Alessandro; Gozzi, Daniele; G., Ferraris; L., Lazzarini. - In: JOURNAL OF PHYSICAL CHEMISTRY. C. - ISSN 1932-7447. - STAMPA. - 115:22(2011), pp. 11023-11029. [10.1021/jp203149v]
High temperature resistivity of dense mats of SWCNT bundles
LATINI, ALESSANDRO;GOZZI, Daniele;
2011
Abstract
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-Gruneisen 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
