Magnetic orientation and magnetic properties of a single carbon nanotube

Carbon nanotubes were suspended in carbon tetrachloride and placed in magne tic fields of < 80.0 kOe at 310 K. Scanning electron microscopy showed that a single and free nanotube was oriented with the tube axis parallel to the fields. From the Boltzmann distribution of tube directions, the anisotropy of susceptibilities parallel (chi (parallel to)) and perpendicular (chi (p erpendicular to)) to the tube axis is estimated to be chi (parallel to) - c hi (perpendicular to) similar to (9 +/- 5) x 10(-6) emu per mole of carbon atoms (chi (perpendicular to) < chi (parallel to) < 0).