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 effe ct of Ar+ and H+ ion bombardment on a highly oriented pyrolitic graphite sa mple. Ion beam fluences in the range 1O(14) to 4 x 10(16) cm(-2) were used with an ion impact energy of 5 keV. For a low ion fluence (of Ar+ and H+), the low energy pi-plasmon of graphite is shifted toward lower energies, whi le for higher fluences (>10(16) cm(-2)), the plasmon vanishes behind an inc reasing background. In the case of H+ ion bombardment, supplementary chemic al reactions take place on the surface, and we report C-H stretching modes induced by the bombardment. We relate the above observations with structura l and chemical modifications induced by the ion bombardment and compare wit h previous results. (C) 2000 Published by Elsevier Science B.V. All rights reserved.