Comparison of AES chemical shifts with XPS chemical shifts

Scanning Auger microprobe equipped with a concentric hemispherical analyzer allows us to measure AES spectra with high-energy resolution. The question is the extent of chemical state information obtainable by AES. XPS chemical shifts and AES chemical shifts, derived from transition energies available from literature, have been compared for many compounds. The mean values were found to be for peak shift 1.71 eV in the case of XPS and −3.86 eV for AES, and the standard deviations were 2.38 eV for XPS and 3.62 eV for AES. We found that the chemical shifts in AES were generally 1.5 times larger than in XPS. For some elements such as Fe, Co, Ni, and Cu, the AES chemical shifts are exceptionally small, but the peak shapes differ depending on the chemical states.