Magnetic field induced delocalization in multi-wall carbon nanotube-polystyrene composite at high fields

Bhatia, Ravi and Galibert, Jean and Menon, Reghu (2014) Magnetic field induced delocalization in multi-wall carbon nanotube-polystyrene composite at high fields. In: CARBON, 69 . pp. 372-378.

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Abstract

In well dispersed multi-wall carbon nanotube-polystyrene composite of 15 wt%, with room temperature conductivity of similar to 5 S/cm and resistivity ratio R-2K/R-200K] of similar to 1.4, the temperature dependence of conductivity follows a power-law behavior. The conductivity increases with magnetic field for a wide range of temperature (2-200 K), and power-law fits to conductivity data show that localization length (xi) increases with magnetic field, resulting in a large negative magnetoresistance (MR). At 50T, the negative MR at 8 K is similar to 13% and it shows a maximum at 90K (similar to 25%). This unusually large negative MR indicates that the field is delocalizing the charge carriers even at higher temperatures, apart from the smaller weak localization contribution at T < 20 K. This field-induced delocalization mechanism of MR can provide insight into the intra and inter tube transport. (C) 2013 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	CARBON
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copyright for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	11 May 2014 06:37
Last Modified:	11 May 2014 06:37
URI:	http://eprints.iisc.ac.in/id/eprint/48903

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