Electrical properties of C⁴⁺ irradiated single‐walled carbon nanotube paper

Abstract

Single‐walled carbon nanotube (SWNT) networks have been irradiated with a 12C4+ ion beam (ion energy 23 MeV) to investigate changes to their properties. Measurements of the Raman D‐line show that the irradiation produces structural defects throughout SWNT paper of thickness 40 μm, with a linear increase in defects at the back side of the sample, but a saturating tendency occurring at the front (irradiated) side. The resistance of the samples also increases linearly with irradiation dose. The temperature dependence of the conductivity of the samples is changed progressively by the irradiation: whereas the pristine sample exhibits mixed metallic‐nonmetallic character consistent with the usual model of metallic conduction interrupted by thin barriers through which fluctuation‐assisted tunnelling occurs, the temperature dependence loses its metallic character and follows three‐dimensional variable‐range hopping for the most irradiated sample. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Coherence in defect evolution data for the ion beam irradiated graphene

“…It is worth noting that the maximum I (D) was previously observed at the inter-defect distance of ~3 nm for low energy (90 eV) Ar + bombardment 21 . This implies that the ion dose required to obtain the maximum I (D)/ I (G) depends on the ion species 28 , 29 . Moreover, the I (D)/ I (G) also differs for different irradiation energies.…”

Ion and electron irradiation-induced effects in nanostructured materials

“…By contrast, high energy irradiation of the samples with 23 MeV C 4+ ions did not give rise to any enhancement in conductivity. 455 An increase in electrical conductivity of carbon nanotube sheets irradiated with Ar and H ions at a temperature of 800 K has also been reported. 456 The conductivity improvement was associated with the formation of covalent cross-links between nanotubes induced by the ion beam irradiation at the elevated temperature.…”

Modifying the electronic structure of semiconducting single-walled carbon nanotubes byAr+ion irradiation

“…15 It was shown that ion-irradiation-induced double vacancies ͑DVs͒, in comparison to single vacancies ͑SVs͒, strongly reduce the conductivity of metallic tubes. The effects of irradiation in more complicated systems, such as SWNT bundles 16 and films, 17,18 have also been studied and interesting effects such as an increase in the conductance after moderate irradiation dose have been reported. 17 In the transport experiments discussed above, only indirect information on the type of defects can be deduced.…”