ELECTRONIC-STRUCTURE OF 0.5 KEV AR+ IRRADIATED GRAPHITE

The effect of keV ion irradiation on the electronic structure of highl y oriented pyrolytic graphite has been investigated by means of electr onic spectroscopies. Samples were irradiated by a 0.5 keV Ar+ beam wit h fluences from 3 x 10(14) up to 3 x 10(15) ions/cm2. In order to inve stigate the relationship between initial (crystalline) and final (amor phous) structure in ion beam processing, we have compared the electron ic states of graphite with those of damaged diamond and polystyrene. R esults indicate that the process of amorphization by ion beam is very fast and it stabilizes after a dose corresponding to about one atomic monolayer, producing the same type of amorphous carbon regardless of t he virgin material.