The effect of annealing on the electronic properties of nanotubes has
been studied. The conduction ESR intensity is temperature-independent
for both annealed and non-annealed nanotubes. However, the g-value of
the nanotubes and its temperature dependence change significantly afte
r annealing. These results suggest that some types of defects are pres
ent in the nanotubes which are then removed by the annealing process.
The ESR studies of the annealed nanotubes indicate that the intrinsic
electronic properties of nanotubes are quite different from those of g
raphite.