The Hydration Structure at Yttria-Stabilized Cubic Zirconia (110)-Water Interface with Sub-Angstrom Resolution

The interfacial hydration structure of yttria-stabilized cubic zirconia (110) surface in contact with water was determined with ~0.5 Å resolution by high-resolution X-ray reflectivity measurement. The terminal layer shows a reduced electron density compared to the following substrate lattice layers, which indicates there are additional defects generated by metal depletion as well as intrinsic oxygen vacancies, both of which are apparently filled by water species. Above this top surface layer, two additional adsorbed layers are observed forming a characteristic interfacial hydration structure. The first adsorbed layer shows abnormally high density as pure water and likely includes metal species, whereas the second layer consists of pure water. The observed interfacial hydration structure seems responsible for local equilibration of the defective surface in water and eventually regulating the long-term degradation processes. The multitude of water interactions with the zirconia surface results in the complex but highly ordered interfacial structure constituting the reaction front.ope

FT-IR STUDY OF THE OH SURFACE GROUPS ON CORDIERITE AEROGEL

Nous avons étudié une cordiérite à haute surface spécifique par spectroscopie infrarouge en transmission. Après activation des échantillons, nous avons mis en évidence la présence des groupes hydroxyles. L'action du méthanol et l'échange isotopique avec le deutérium ont prouvé que tous ces groupes sont liés aux atomes de silicium de surface.A high specific surface area cordierite has been investigated by infrared transmission spectroscopy. After activation of the samples, we have evidenced the presence of hydroxyl groups. Treatments with methanol and isotopic exchange with deuterium have proved that all of them are bound to the surface silicium atoms

Molybdenum and titanium nitride films processed in expanding (Ar-N2-H2) microwave plasma

International audienc