P. A. P. Nascente

L3M4,5M4,5 Auger transitions and valence hole screening of the 4d metals

High kinetic energy (2000–3000 eV) L3M4,5M4,5 Auger transitions (excited by Bremsstrahlung) are reported for the 4d series. The valence electron contribution to the measured Auger parameters was extracted from the data by exploiting systematics predicted theoretically. The systematic dependence on atomic number clearly manifests the effect of the nature of the screening charge and agrees remarkably well with independent theoretical calculations of metallic renormalization. Corresponding valence contributions for the 3d and 5d metals exhibit similar screening systematics.

LMM and LMN Auger spectra of Nb, Mo, Pd and Ag: an investigation by X-ray excited Auger electron spectroscopy

The authors present high-resolution measurements of several of the LMM and LMN Auger spectra of Nb, Mo, Pd and Ag excited by bremsstrahlung. Because of their high energy (2.0-3.5 keV), these spectra have not been reported in the literature. Assignments of the peaks are made based upon energy and intensity considerations.

L3M4,5M4,5 Auger transitions and screening mechanisms in the 4d metals

Abstract We have measured Bremsstrahlung-excited L 3 M 4,5 M 4,5 Auger spectra of Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, and Sb. These core level spectra are sufficiently narrow and have lineshapes simple enough to permit determining the corresponding Auger parameters. By exploiting the theoretical systematics of the excited-atom version of the quasi-atomic model of core hole screening, the valence electron contribution to the Auger parameter can be extracted. Comparison of the L 3 M 4,5 M 4,5 and M 5 N 4,5 N 4,5 results for the 4d metals indicates that the d-band holes appear to behave like core holes, except possibly for Nb and Pd.

CARACTERIZAÇAO POR XPS DE CATALISADORES DE ÔXIDOS DE Al E Zn

As razoes atomicas Al/Al+Zn e S/Al+Zn para catalisadores de oxidos de Al e Zn, obtidos por coprecipitacao a partir dos sulfatos metalicos, sao determinadas por XPS (espectroscopia de fotoeletrons excitados por raio-X). nEsses teores sao comparados aos obtidos por analise quimica e correlacionados com dados de ensaio catalitico da conversao do etanol em butadieno.

APLICAÇÕES DO MODELO QUASE-ATÔMICO A LIGAS DE PALÁDIO E OURO

O modelo quase-atomico(quasi-atomic model - quam)(1,2) relaciona a variacao do nivel de Fermi em ligas bimetalicas de metal nobre ao deslocamento Auger do mesmo. nMedidas experimentais dos deslocamentos Auger do ouro no sistema PdxAu1-x, obtidas pela tecnica de espectroscopia Auger excitado por bremsstrahlung(bremsstrahlung excited Auger spectroscopy - BEAS) (3-5), comprovam a validade do modelo.