On the Auger-photoelectron coincidence spectroscopy spectra of Cu(100), Cu metal and CuOx/Cu surface

Abstract

The M 3–VV Auger-photoelectron coincidence spectroscopy (APECS) spectrum of Cu(100) and the L 3–VV APECS spectra of Cu metal and CuOx/Cu surface are analyzed in detail. The narrowing and energy shift of the photoelectron line in the M 3–VV APECS spectrum is well predicted by the present theory. The spectrum shows the presence of the M 2–M 3(V)–VV(V) decay in which a hole in the 4s band hops away prior to the decay of M 3 hole. The analysis of the L 3 photoelectron spectra of Cu metal measured in coincidence with the 3F or 1G Auger line raises a question concerning the presence of two different core–hole states upon the L 3 level ionization recently proposed by Thurgate and Jiang [Surf. Sci. 466 (2000) L807]. The analysis of the L 3–VV APECS spectrum of CuOx/Cu shows that the final-state charge–transfer interaction plays an important role in CuO.