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The aim of this work was to get a better understanding of the O 1s binding energies Eb(O1s) in complex glasses of interest in nuclear waste storage in relationship with the mean charge on the oxygen atoms, relevant to acidic/basic properties of the glass. Three different glasses were considered: an aluminum borosilicate, a lanthanum aluminosilicate and a calcium aluminosilicate. The O1s binding energies were measured for each glass, along with individual simple oxides. The oxygen charges were estimated by an empirical method based on the electronegativity equalization principle. We show that for the first two glasses, the O 1s binding energy shift is driven by the changes in the oxygen charge induced by mixing the oxides to obtain the glass For the latter glass however, Madelung effects are of prime importance and the Eb(O1s) value of the glass cannot be predicted from the values in the individual oxides.

Reflection Electron Energy Loss Spectroscopy (REELS) is a valuable tool to characterize the electronic structure of insulating surfaces and nanometric films. The REELS inelastic single scattering cross section obtained after removing multiple losses is related to the complex dielectric function in the surface layers. Moreover the probing depth can be varied by changing the primary energy of electrons. One can expect in essence to obtain non-destructive REELS depth profiles, where the evolution of the REELS spectrum translates to the in-depth evolution of the dielectric constant. We present a REELS study of pure and Nb-doped SrTiO3 single crystals, with primary energies ranging from 200 eV to 1500 eV so as to vary the probing depth between 0.7 and 3 nm. The resulting variations in the shape of the spectra are qualitatively interpreted by considering the energy loss functions corresponding to a double interface SrTiO3/carbon monolayer/vacuum, on the basis of the experimental dielectric function derived from TEELS measurements on strontium titanate and amorphous carbon.

We show that SEXAFS can be used to determine the growth law of subnanometric particles. In the case of copper deposited on alumina, the dynamic scaling of the mean cluster size distribution, in the radius range 2-10 Å, is demonstrated. This scaling is explained by the coalescence of copper clusters, as in breath figures due to the condensation of liquid droplets. This growth law can be fitted by a power law with an exponent 1.2 and is fairly well reproduced by a purely stochastic coalescence model.