Transport and localization in single-walled carbon nanotubes

Journal Article · Sat Aug 01 04:00:00 EDT 1998 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.56501· OSTI ID:292675

Fuhrer, M S; Varadarajan, U; Holmes, W; Richards, P L; Delaney, P; Louie, S G; Zettl, A ^[1]

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1. Department of Physics, University of California, Berkeley, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

We have measured the electrical transport properties of mats of single-walled carbon nanotubes (SWNT) as a function of applied electric and magnetic fields. We find that at low temperatures the resistance as a function of temperature R(T) follows the Mott variable range hopping (VRH) formula for hopping in three dimensions. Measurement of the electric field dependence of the resistance R(E) allows for the determination of the Bohr radius of a localized state a{approx}650 nm. The magnetoresistance (MR) of SWNT mat samples is large and negative at all temperatures and fields studied, and can be qualitatively described by theories of MR for VRH systems. The Hall coefficient R{sub H} is positive and nearly temperature-independent. The sign of R{sub H} agrees with the sign of the thermopower. The small magnitude of R{sub H} suggests a large carrier density, but may be the result of cancellation of electron and hole terms. {copyright} {ital 1998 American Institute of Physics.}

• Research Organization: Lawrence Berkeley National Laboratory
• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 292675
• Report Number(s): CONF-980379--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 442; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON
CARRIER DENSITY
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
ELECTRONIC STRUCTURE
HALL EFFECT
MAGNETIC FIELDS
MAGNETORESISTANCE
TEMPERATURE DEPENDENCE