Electron Paramagnetic Resonance and Electron-Positron Annihilation in Multilayer Carbon Nanotubes with Defects

One- and multilayer carbon nanotubes (CNT) different by imperfection of graphene layers and their packing at formation of multilayer CNT are investigated by positron spectroscopy (PS) (with angular distribution of annihilation photons) and electron paramagnetic resonance methods. As revealed, with growth of imperfection, the number of resonating electrons giving the contribution to EPR-signal intensity increases by 1-2 order. Radii of localization of electrons wave function, which are commensurable with lengths of it (0.115 +/- 0.005 nm) and a (0.061 +/- 0.005 nm) bonds, are determined, and their double sum is equal to interlayer distance of 0.352 nm. As also revealed, resonant absorption of microwave radiation occurs at frequency of 9.9 GHz in CNT on the paramagnetic centres such as quasi-free electrons and unsaturated a bonds. EPR and PS methods can be used for both certification of CNT arrays and identification of defects within them.