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 (dρ/dT> 0) is an intrinsic property of the bulk material, and that the system remains metallic even at low temperature where dρ/dT< 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.