Tanty, Narendra and Patra, Ananya and Maity, Krishna Prasad and Prasad, V (2019) Tuning magnetoresistance and electrical resistivity by enhancing localization length in polyaniline and carbon nanotube composites. In: BULLETIN OF MATERIALS SCIENCE, 42 (5).
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Abstract
We report low temperature electrical resistivity and magnetoresistance (MR) measurements of conducting polyaniline (PANI) and multiwalled-carbon nanotube (MWCNT) composites. We have used an in-situ oxidative polymerization method to synthesize hydrochloric acid-doped PANI composites with MWCNT weight percentages of 0, 5, 10 and 15. The temperature dependence of resistivity is studied from room temperature to 4.2K and analysed by a Mott variable range hopping (VRH) model. The resistivity increases from 1.1 x 10 -3 m at 300K to 65.75 m at 4.2 K, almost four orders of the magnitude change with temperature for pure PANI. Whereas the PANI composite with 15% MWCNTs shows less variation from 4.6x10 -4 to 3.5x10 -2 m. The huge change in resistivity is due to the localization of charge carriers in the presence of disorder. At 4.2K MR shows transition from positive to negative with higher MWCNT loading. Samples with 5 and 10% MWCNTs show positive MR, whereas the 15% MWCNT loaded sample shows negative MR. The positive and negative MR are discussed in terms of the wave function shrinkage effect and quantum interference effect on VRH conduction.
| Item Type: | Journal Article |
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| Publication: | BULLETIN OF MATERIALS SCIENCE |
| Publisher: | INDIAN ACAD SCIENCES |
| Additional Information: | copyright for this article is belongs to INDIAN ACAD SCIENCES |
| Keywords: | Resistivity; magnetoresistance; disorder; localization |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 30 Jul 2019 06:18 |
| Last Modified: | 30 Jul 2019 06:18 |
| URI: | http://eprints.iisc.ac.in/id/eprint/63157 |
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