Negative to positive magnetoresistance transition in functionalization of carbon nanotube and polyaniline composite

Maity, Krishna Prasad and Tanty, Narendra and Patra, Ananya and Prasad, V (2018) Negative to positive magnetoresistance transition in functionalization of carbon nanotube and polyaniline composite. In: MATERIALS RESEARCH EXPRESS, 5 (3).

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Abstract

Electrical resistivity and magnetoresistance(MR) in polyaniline(PANI) with carbon nanotube(CNT) and functionalized carbon nanotube(fCNT) composites have been studied for different weight percentages down to the temperature 4.2 Kand up to magnetic field 5 T. Resistivity increases significantly in composite at low temperature due to functionalization of CNT compared to only CNT. Interestingly a transition from negative to positive magnetoresistance has been observed when the filler is changed from pure CNT to functionalized CNT after a certain percentage (10wt%) as the effect of more disorder in fCNT/PANI composite. This result depicts that the MR has strong dependency on disorder in the composite system. The transition of MR has been explained on the basis of polaron-bipolaron model. The long range Coulomb interaction between two polarons screened by disorder in the composite of fCNT/PANI, increases the effective on-site Coulomb repulsion energy to form bipolaron which leads to change the sign of MR from negative to positive.

Item Type:	Journal Article
Publication:	MATERIALS RESEARCH EXPRESS
Publisher:	IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Additional Information:	Copy right for the article belong to IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	12 Apr 2018 18:49
Last Modified:	12 Apr 2018 18:49
URI:	http://eprints.iisc.ac.in/id/eprint/59525

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