Electron–electron interaction in multiwall carbon nanotubes

The magnetic susceptibility χ of pristine and brominated arc-produced sample of multiwall carbon nanotubes was measured from 4.2 to 400 K. An additional contribution Δχ(T) to diamagnetic susceptibility χ(T) of carbon nanotubes was found at T<50 K for both samples. It is shown that Δχ(T) are dominated by quantum correction toχ for interaction electrons (interaction effects-IE). The IE shows a crossover from two-dimensional to three-dimensional at B=5.5 T. The effective interaction between electrons for interior layers of nanotubes has been found to be repulsive and the electron–electron interaction λc was estimated to be λc∼0.26.