Ethylene and acetylene adsorption on Cu(111) and Pt(111) studied by Auger spectroscopy

High resolution, electron impact excited, carbon Auger spectra of ethylene and acetylene adsorbed on Cu(111) and Pt(111) are compared. The spectra of ethylene on the two metals provide the first example of the sensitivity of AES to the nature of metal-adsorbate bonding for molecular adsorbates. The acetylene spectra are identical on the two metals. The changes in the carbon Auger spectra resulting from thermal decomposition of the two adsorbates on Pt(111) are discussed in the context of results from electron energy loss spectroscopy.