Abstract
It is found that the KLL carbon Auger spectrum is strongly influenced by the chemical state of the carbon. This is expected since the L electrons in carbon are the valence electrons. We have found that it is possible to distinguish between surface carbon and adsorbed CO on the basis of this carbon Auger spectrum. This sensitivity to the chemical state of the emitting atom when the Auger electron is ejected from the valence band suggests that this measurement may be useful in determining bonding of surface atoms.