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Les alliages amorphes Cu−Ti donnent une forte diffusion centrale apres hydrogenation. Celle-ci est analysee par diffusion anormale des rayons X sur les seuils K du cuivre et du titane. On peut alors conclure a la presence de tres petits agregats d'hydrure de titane de composition TiH 2 . Ces resultats sont en accord avec ceux obtenus par diffraction des neutrons en utilisant soit l'hydrogene soit le deuterium pour l'hydrogenation des echantillons

Experiences de diffraction de neutrons a petits angles sur des alliages amorphes Pd 80 Si 20

Mössbauer experiments have been performed on Nafion ion exchange membranes neutralized with iron chloride. The recoilless fraction falls to zero at a temperature which depends on the water content, showing that the rigidity of the local ion environment is greatly influenced by the amount of water retained in these membranes. Two different iron sites are defined, whose relative intensities vary with water content. One of the doublets is attributed to a (Fe2+, H 2O complex whose hyperfine parameters are essentially independent of the quantity of water. The second doublet is attributed to a less hydrated species. No evidence of magnetic hyperfine structure is found, even at 4.2 K.

Experiences de diffraction de neutrons sur des alliages amorphes Cu x Ti 1-x avec differentes teneurs en hydrogene ou en deuterium. Modele structural