Abstract - We have investigated the low-energy (100 eV) D+ and H+ ion irradiation effects on the structural and chemical properties of highly oriented pyrolytic graphite (HOPG). Structural disorder due to the ion irradiation was identified by the Raman spectroscopy, the D+ irradiation giving rise to greater structural disorder than the H+ irradiation. Only sp2 bonding was identified in the X-ray photoemission spectroscopy of the D+-irradiated HOPG, indicating no change in the surface chemical structure. The H+ irradiation, on the other hand, gave rise to sp3 bonding and pi-pi* transition, the sp3 bonding increasing with increasing irradiation dose. It is thus shown that the chemical properties of the HOPG surface may be sensitively modified by the low-energy H+ ion irradiation, but not by the low-energy D+ ion irradiation.

http://dx.doi.org/10.1063/1.4838156