X-ray photoelectron and Raman spectroscopic studies of MeV proton irradiated graphite

✍ Scribed by S. Mathew; B. Joseph; B.R. Sekhar; B.N. Dev

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 292 KB
• Volume: 266
• Category: Article
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2008.03.233

✦ Synopsis

Poly-crystalline graphite samples were irradiated using 2.25 MeV H + ions with a fluence of 2 Â 10 17 ions/cm 2 . Magnetic ordering in highly oriented pyrolytic graphite samples have been reported earlier under the similar irradiation conditions [Esquinazi et al., Phys. Rev. Lett. 91 (2003) 227201]. In that study, the authors attribute the observed irradiation induced magnetic ordering to the formation of a mixed sp 2 -sp 3 hybridized carbon atoms. In the present study, we report the X-ray photoelectron and Raman spectroscopic studies on pristine and irradiated samples. Irradiated samples are found to show an increased number of sp 3 hybridized carbon atoms. However, the Raman spectrum, specially the second order data, do indicate that the nature of the graphene lattice structure has been preserved in the irradiated samples. The mechanisms for the irradiation induced enhancement in sp 3 hybridization are discussed.