Departmental Papers (MSE)

Document Type

Journal Article

Date of this Version

February 2003

Comments

Postprint version. Published in Journal of Applied Physics, Volume 93, Issue 4, 15 February 2003, pages 2157-2163.
Publisher URL: http://dx.doi.org/10.1063/1.1536733

Abstract

Thick films of single wall carbon nanotubes (SWNT) exhibiting in-plane preferred orientation have been produced by filter deposition from suspension in strong magnetic fields. We characterize the field-induced alignment with x-ray fiber diagrams and polarized Raman scattering, using a model which includes a completely unaligned fraction. We correlate the texture parameters with resistivity and thermal conductivity measured parallel and perpendicular to the alignment direction. Results obtained with 7 and 26 Tesla fields are compared. We find no significant field dependence of the distribution width, while the aligned fraction is slightly greater at the higher field. Anisotropy in both transport properties is modest, with ratios in the range 5–9, consistent with the measured texture parameters assuming a simple model of rigid rod conductors. We suggest that further enhancements in anisotropic properties will require optimizing the filter deposition process rather than larger magnetic fields. We show that both x-ray and Raman data are required for a complete texture analysis of oriented SWNT materials.

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Date Posted: 31 July 2005

This document has been peer reviewed.