High-resolution STEM-HAADF microscopy on a γ-AlO supported MoS catalyst-proof of the changes in dispersion and morphology of the slabs with the addition of citric acid.

Atomic-scale images of MoS slabs supported on γ-AlO were obtained by high-resolution scanning transmission electron microscopy equipped with a high angular annular dark field detector (HR STEM-HAADF). These observations, obtained for sulfide catalysts prepared with or without citric acid as a chelating agent, evidenced variations in morphology (shape) and size of the MoS nanoslabs, as detected indirectly by the adsorption of CO followed by infrared spectroscopy. Quantitative dispersion values and a morphology index (S-edge/M-edge ratio) were determined from the slabs observed.

Distribution of Eu and Eu Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study.

We present a cathodoluminescence study of the spatial distribution of Eu and Eu dopants in hydroxyapatite powders. The results demonstrate that the distribution of europium ions in the hydroxyapatite lattice depends on their valence state. Monochromatic cathodoluminescence images from prismatic powders show that although the Eu is distributed homogeneously in the entire powder volume, the Eu is present mainly at the powder edges.