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RESEARCH PRODUCT
Local structure of gallate proton conductors
Antonino MartoranaFrancesco GianniciAlessandro LongoLuisa SciortinoDiego Messanasubject
HistoryEXAFS gallate XRD proton conductorChemistryHydrogen bondchemistry.chemical_elementGallateCrystal structureComputer Science ApplicationsEducationCrystallographyChemical bondVacancy defectX-ray crystallographyLanthanumProton conductordescription
Lanthanum barium gallate proton conductors are based on disconnected GaO4 groups. The insertion of hydroxyls in the LaBaGaO4 network proceeds through self-doping with Ba2+, consequent O2- vacancy formation to fulfill charge neutrality. With a structural investigation on self-doped LaBaGaO4 oxides using synchrotron XRD and EXAFS on the Ga K-edge, we find that: (a) the GaO4 tetrahedra retain their size throughout the whole series; (b) the GaO4 tetrahedra rotate as rigid bodies on hydration, leading to the formation of a network of shorter O-O configurations that are stabilized by hydrogen bonds; (c) contraction of the lattice occurs along the a unit cell axis, as a consequence of an overall structural rearrangement of the hydrated solid.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2009-11-01 |