Controlled orientation of ellipsoidal fullerene C70 in carbon nanotubes

Density functional theory calculations predict two orientations for ellipsoidal C-70 fullerenes inside single-walled carbon nanotubes (SWNTs) of different sizes: transverse orientation for C-70 in (11,11) nanotubes (d=14.9 Angstrom) and longitudinal orientation for C-70 in (10,10) nanotubes (d=13.6 Angstrom). SWNTs with these diameters have been prepared and filled with the C-70 fullerenes, and characterized by Raman spectroscopy and high-resolution transmission electron microscopy, showing the orientations predicted by theory. (C) 2004 American Institute of Physics.