A sensitive technique for detecting chemical changes by AES

The measurement of Auger currents and their associated peak to peak heights from the first derivative spectra has provided the basis for an analysis of the various stages of nitric oxide absorption onto a W(110) surface at room temperature. This chemisorption system is a test case for the method since the nitrogen and oxygen KLL Auger spectra in first derivative form look similar at all stages of adsorption. The results indicate that the method is sensitive to chemical changes in the adsorbate to an extent comparable with XPS.