Contribution of the fluorescence to conversion electron yield X-ray absorption fine-structure measurements

International audienceInfluence of an extra electron yield induced by the fluorescence process has been experimentally shown and analytically described. Analyse of the Conversion Electron Yield signal induced by pure bulk silver (Ag K-edge) and pure bulk nickel or copper recovered by a thin iron layer (Ni and Cu K-edges) has been performed. This fluorescence-electron yield leads to enhance the edge-height to modify the shape of the XANES and to decrease the EXAFS amplitude. Extrapolation of the model concerning unrecovered bulk samples was carried out in order to explain the EXAFS amplitude reduction often observed in CEY measurements referring to that obtained in the transmission mode. Such reduction / increases with the atomic number Z of the studied element. / can be considered as negligible for low-Z element (Ni and Cu). It becomes important for high-Z element. K-dependence of the amplitude reduction is rather limited and such reduction can be simply explained by a proportional factor. In order to correct this unwanted effect, theoretical calculation process can be performed or sample structure can be especially designed to minimise it. Thin films deposited on substrate composed of low-Z element do not generate significantly such extra electron yield