Irradiation Effects in Graphite Induced by Helium IONS: Surface, Structural, and Chemical Analyses

The physical and chemical effects of helium ion irradiation on the nuclear grade graphite are studied by employing a plasma focus device. The device emits ion pulse having energy in the range of a few ke V to MeV and flux of ~ 1025 m-2s-1. The reference and ion irradiated graphite samples are analyzed by using different types of characterization tools in order to ascertain radiation induced effects. The field emission scanning electron microscopy confirms the formation of multi-modal spherical and elongated agglomerated structures on irradiated samples surface with increase in agglomerate size with increasing number of irradiation shots. The atomic force micrographs reveal an increase in surface roughness due to ion irradiation. The Raman study reads a decrease in the La value after ion irradiation and suggests a loss in crystallinity of the irradiated samples. The X-ray diffraction patterns also corroborate the Raman results. The possibility of transformation in hybridization is confirmed from X -ray photoelectron spectroscopy characterization. The results obtained suggest that the present experimental technique can be adopted to produce graphitic carbon nanostructures which may find application in the field of medical drug delivery and electrode industry.