Magnetic orientation of carbon nanotubes at temperatures of 231 K and 314 K

Carbon nanotubes were placed in magnetic fields of less than or equal to80.0 kOe at temperatures of 231 K and 314 K. Scanning electron microscopy showed that nanotubes were oriented with the tube axis parallel to the fields. It was also observed that the probability of the orientation became higher, when the temperature was raised from 231 K to 314 K. The anisotropy in the susceptibilities parallel chi(parallel to) and perpendicular chi(perpendicular to) to the tube axis is suggested to increase with rise in temperature: chi(parallel to) - chi(perpendicular to) = (4 +/- 2) x 10(6) emu mol(1) (per mol of carbon atoms) at 231 K and chi(parallel to) - chi(perpendicular to) = (45 +/- 27) x 10(6) emu mol(1) at 314 K.