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

Abstract

Carbon nanotubes were placed in magnetic fields of ⩽ 80.0 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 X∥ and perpendicular X ⊥ to the tube axis is suggested to increase with rise in temperature: X∥ − X⊥ = (4 ± 2) × 10−6 emu mol−1 (per mol of carbon atoms) at 231 K and X∥ − X⊥ = (45 ± 27) × 10−6 emu mol−1 at 314 K.