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Purification/annealing of graphene with 100-MeV Ag ion irradiation.

Kumar S, Tripathi A, Singh F, Khan SA, Baranwal V, Avasthi DK - Nanoscale Res Lett (2014)

Bottom Line: We report swift heavy ion (SHI) irradiation-induced annealing and purification effects in graphene films, similar to that observed in our studies on fullerenes and carbon nanotubes (CNTs).This indicates that SHI induces annealing effects at lower fluences.The results suggest that SHI irradiation fluence may be used as one of the tools for defect annealing and manipulation of the number of graphene layers. 60.80.x; 81.05.ue.

View Article: PubMed Central - HTML - PubMed

Affiliation: Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067, India.

ABSTRACT

Unlabelled: Studies on interaction of graphene with radiation are important because of nanolithographic processes in graphene-based electronic devices and for space applications. Since the electronic properties of graphene are highly sensitive to the defects and number of layers in graphene sample, it is desirable to develop tools to engineer these two parameters. We report swift heavy ion (SHI) irradiation-induced annealing and purification effects in graphene films, similar to that observed in our studies on fullerenes and carbon nanotubes (CNTs). Raman studies after irradiation with 100-MeV Ag ions (fluences from 3 × 10(10) to 1 × 10(14) ions/cm(2)) show that the disorder parameter α, defined by I D/I G ratio, decreases at lower fluences but increases at higher fluences beyond 1 × 10(12) ions/cm(2). This indicates that SHI induces annealing effects at lower fluences. We also observe that the number of graphene layers is reduced at fluences higher than 1 × 10(13) ions/cm(2). Using inelastic thermal spike model calculations, we estimate a radius of 2.6 nm for ion track core surrounded by a halo extending up to 11.6 nm. The transient temperature above the melting point in the track core results in damage, whereas lower temperature in the track halo is responsible for annealing. The results suggest that SHI irradiation fluence may be used as one of the tools for defect annealing and manipulation of the number of graphene layers.

Pacs: 60.80.x; 81.05.ue.

No MeSH data available.


Related in: MedlinePlus

The plot of disorder parameter α (ID/IG) with fluence.
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Figure 3: The plot of disorder parameter α (ID/IG) with fluence.

Mentions: The defects induced in carbon-based materials are studied using disorder parameter α defined by ID/IG ratio, where the ID and IG are the intensity of D and G peaks, respectively, in the Raman spectrum. It measures the disorder present in the sample which may be due to defects or misalignment in the graphene sample. Samples of lower disorder have low value of α, and a high value of α indicates larger amount of disorder. Since there are variations in different parts of the sample, we have normalized the value of ID/IG of irradiated part with the value of ID/IG of pristine part, and these normalized ratios have been studied for further analysis. The variation of α for different fluences is plotted in Figure 3.


Purification/annealing of graphene with 100-MeV Ag ion irradiation.

Kumar S, Tripathi A, Singh F, Khan SA, Baranwal V, Avasthi DK - Nanoscale Res Lett (2014)

The plot of disorder parameter α (ID/IG) with fluence.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4012553&req=5

Figure 3: The plot of disorder parameter α (ID/IG) with fluence.
Mentions: The defects induced in carbon-based materials are studied using disorder parameter α defined by ID/IG ratio, where the ID and IG are the intensity of D and G peaks, respectively, in the Raman spectrum. It measures the disorder present in the sample which may be due to defects or misalignment in the graphene sample. Samples of lower disorder have low value of α, and a high value of α indicates larger amount of disorder. Since there are variations in different parts of the sample, we have normalized the value of ID/IG of irradiated part with the value of ID/IG of pristine part, and these normalized ratios have been studied for further analysis. The variation of α for different fluences is plotted in Figure 3.

Bottom Line: We report swift heavy ion (SHI) irradiation-induced annealing and purification effects in graphene films, similar to that observed in our studies on fullerenes and carbon nanotubes (CNTs).This indicates that SHI induces annealing effects at lower fluences.The results suggest that SHI irradiation fluence may be used as one of the tools for defect annealing and manipulation of the number of graphene layers. 60.80.x; 81.05.ue.

View Article: PubMed Central - HTML - PubMed

Affiliation: Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067, India.

ABSTRACT

Unlabelled: Studies on interaction of graphene with radiation are important because of nanolithographic processes in graphene-based electronic devices and for space applications. Since the electronic properties of graphene are highly sensitive to the defects and number of layers in graphene sample, it is desirable to develop tools to engineer these two parameters. We report swift heavy ion (SHI) irradiation-induced annealing and purification effects in graphene films, similar to that observed in our studies on fullerenes and carbon nanotubes (CNTs). Raman studies after irradiation with 100-MeV Ag ions (fluences from 3 × 10(10) to 1 × 10(14) ions/cm(2)) show that the disorder parameter α, defined by I D/I G ratio, decreases at lower fluences but increases at higher fluences beyond 1 × 10(12) ions/cm(2). This indicates that SHI induces annealing effects at lower fluences. We also observe that the number of graphene layers is reduced at fluences higher than 1 × 10(13) ions/cm(2). Using inelastic thermal spike model calculations, we estimate a radius of 2.6 nm for ion track core surrounded by a halo extending up to 11.6 nm. The transient temperature above the melting point in the track core results in damage, whereas lower temperature in the track halo is responsible for annealing. The results suggest that SHI irradiation fluence may be used as one of the tools for defect annealing and manipulation of the number of graphene layers.

Pacs: 60.80.x; 81.05.ue.

No MeSH data available.


Related in: MedlinePlus