MAGNETIC-SUSCEPTIBILITY OF CARBON STRUCTURES

Measurements of the magnetic moment and susceptibility of diamond, gra phite along and perpendicular to the c axis, C60, and carbon nanotubes are reported as a function of magnetic field (0 < H < 55 kOe) and tem perature (4.5 K < T < 3 10 K). The data on C60 are diamagnetic, confir m previous results, and show the influence of the phase transition nea r 260 K. The data on the nanotubes were taken on a sample containing a distribution of tubes with diameters in the 2 - 10 nm range, and reve al a mostly diamagnetic behavior with a magnetic field and temperature dependence different from graphite.