Structural anisotropy of magnetically aligned single wall carbon nanotube films

Thick films of aligned single wall carbon nanotubes and ropes have been produced by filtration/deposition from suspension in strong magnetic fields. We measured mosaic distributions of rope orientations in the film plane, for samples of different thicknesses. For an $\text{∼1\hspace{0.05em}μ}\mathrm{m}$ film the full width at half maximum (FWHM) derived from electron diffraction is $\text{25°–28°.}$ The FWHM of a thicker film $\text{(∼7\hspace{0.05em}μ}\mathrm{m})$ measured by x-ray diffraction is slightly broader, $\text{35±3°.}$ Aligned films are denser than ordinary filter-deposited ones, and much denser than as-grown material. Optimization of the process is expected to yield smaller FWHMs and higher densities.