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.

Giannici, F., Messana, D., Longo, A., Sciortino, L., Martorana, A. (2009). Local structure of gallate proton conductors. In Journal of Physics: Conference Series. Institute of Phsyics [10.1088/1742-6596/190/1/012077].

Local structure of gallate proton conductors

GIANNICI, Francesco;SCIORTINO, Luisa;MARTORANA, Antonino
2009-01-01

Abstract

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.
2009
14th International Conference on X-ray Absorption Fine Structure
Camerino
26-31 luglio 2009
2009
00
Giannici, F., Messana, D., Longo, A., Sciortino, L., Martorana, A. (2009). Local structure of gallate proton conductors. In Journal of Physics: Conference Series. Institute of Phsyics [10.1088/1742-6596/190/1/012077].
Proceedings (atti dei congressi)
Giannici, F; Messana, D; Longo, A; Sciortino, L; Martorana, A
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/44225
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