Electron spin resonance and microwave resistivity of single-wall carbon nanotubes

We compare the thermal variations of ESR, dc, and microwave resistivity of unoriented bulk single wall carbon nanotube samples. We conclude that the “metallic” high-$T$ behavior $(d\rho /dT>\mathrm{}$ 0) is an intrinsic property of the bulk material, and that the system remains metallic even at low temperature where $d\rho /dT<\mathrm{}$ 0. The spin susceptibility is also independent of $T,$ and a long mean free path implies transport predominantly along the tube axes in bulk material.