Study by HREELS of elementary reactions on graphite surface induced by Ar+ and H+ ion bombardment

We used high-resolution electron energy loss spectroscopy to study the effect of Ar+ and H+ ion bombardment on a highly oriented pyrolitic graphite sample. Ion beam fluences in the range 1O14 to 4×1016 cm−2 were used with an ion impact energy of 5 keV. For a low ion fluence (of Ar+ and H+), the low energy π-plasmon of graphite is shifted toward lower energies, while for higher fluences (>1016 cm−2), the plasmon vanishes behind an increasing background. In the case of H+ ion bombardment, supplementary chemical reactions take place on the surface, and we report CH stretching modes induced by the bombardment. We relate the above observations with structural and chemical modifications induced by the ion bombardment and compare with previous results.