Line shape of the Ag M4,5VV Auger spectra measured by Auger-photoelectron coincidence spectroscopy - art. no. 155102

We present high resolution Ag M5VV and M4VV Auger spectra obtained in coinc idence with 3d(5/2) and 3d(3/2) core photoelectrons, respectively. Auger ph otoelectron coincidence spectroscopy (APECS) was used to separate these ove rlapping Auger lines and determine the intrinsic line shape of each spectru m. As the on-site Coulomb correlation energy U of Ag is comparable to twice the 4d bandwidth, 2W, (i.e., U/2W similar to1), the coincidence Auger spec tra exhibit both atomiclike and bandlike character. We find that whether co nsidered separately or in combination, neither bandlike nor atomiclike line shapes give a satisfactory account of these Auger spectra. Instead, the in trinsic Ag M5VV and M4VV line shapes are well described by the Cini-Sawatzk y theory when it is applied separately to each component of the multiplet s tructure of the 4d(8)5s(2) Auger final state. A fit to the APECS data indic ates that the correlation energy the (1)G(4) multiplet is 4.8+/-0.1 eV. Fur thermore, our analysis indicates that the missing intensity in the vicinity of the F-3(4) multiplet in the Ag M5VV Auger line, which has been noted in previous studies, results from a shift in the spectral weight of this mult iplet component to higher kinetic energy, into the bandlike region of the s pectrum.