9-13 July 2012
Africa/Johannesburg timezone
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Electronic transport in a rope of metal filled single walled carbon nanotubes

Presented by Ms. Siphephile NCUBE on 12 Jul 2012 from 14:30 to 14:50
Type: Oral Presentation
Session: DCMPM1
Track: Track A - Division for Condensed Matter Physics and Materials

Abstract

Filling of single walled nanotubes (SWNT) with chosen materials opens new possibilities of generating a nearly one dimensional structure by encapsulating a nanowire into a nanotube with a very small diameter. To date researchers have done considerable work on filling multi- and double walled nanotubes due to their larger diameters compared to SWNT's. SWNT's provide a platform to study the nanowire-nanotube interaction. High purity SWNT’s were synthesized by laser ablation and filled by a wet chemistry technique. Filling efficiency was investigated through electron microscopy.Raman spectroscopy studies showed a shift in the radial breathing mode frequencies indicating a decrease in diameter as the metal is encapsulated into the nanotube. We investigated the electronic and magnetic properties of individual and bundled nickel filled SWNT's using low temperature and magneto-resistance studies. The bundle of tubes exhibits semimetallic behavior with a T<sup>2</sup> temperature dependence. A very small energy gap has been observed in the I-V characteristics of these samples which show step like features related to resonant tunneling phenomena. On the other hand individual tubes showed a metallic nature from 300K down to 140K and a weakly activated conduction at low temperatures, below 140K complimented by the non exponential I-V characteristics. This study can be used to develop an understanding of the metal-nanotube interaction and the overall effect of the filler material on the electronic and magnetic properties of SWNT for nanoelectronic and spintronic applications.

Award

No

Level

MSC

Supervisor

Somnath Bhattacharyya, Somnath.Bhattacharyya@wits.ac.za, University of the Witwatersrand

Paper

No

Primary authors

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