Mostrar el registro sencillo del ítem
Unravelling Crystal Superstructures and Transformations in the La6−xMoO12−δ (0.6 ≤ x ≤ 3.0) Series: A System with Tailored Ionic/ Electronic Conductivity.
dc.contributor.author | López Vergara, Adrián | |
dc.contributor.author | Vizcaíno-Anaya, Lucía | |
dc.contributor.author | Porras-Vázquez, José Manuel | |
dc.contributor.author | Baldinozzi, Gianguido | |
dc.contributor.author | Dos-Santos-Gómez, Lucía | |
dc.contributor.author | Canales-Vázquez, J. | |
dc.contributor.author | Marrero-López, David | |
dc.contributor.author | Ramírez-Losilla, Enrique | |
dc.date.accessioned | 2023-12-21T11:21:04Z | |
dc.date.available | 2023-12-21T11:21:04Z | |
dc.date.created | 2023-12-18 | |
dc.date.issued | 2020-08-03 | |
dc.identifier.uri | https://hdl.handle.net/10630/28458 | |
dc.description.abstract | Crystalline La6−xMoO12−δ materials with different lanthanum/molybdenum ratios (0.6 ≤ x ≤ 3.0) have been prepared via a freeze-drying precursor route. The influence of the lanthanum content, sintering temperature, and cooling rate on the phase existence range and polymorphism was evaluated. Lanthanum-rich compounds present three different polymorphs: a cubic (disordered) fluorite and two complex rhombohedral superstructures related to the fluorite. For the first time, the structural resolution of these rhombohedral superstructures, 7 × 7 × 1 and 5 × 5 × 1, has been successfully accomplished by neutron powder diffraction and transmission electron microscopy studies. As the La/Mo ratio decreases, the cubic symmetry is stabilized, although a phase transformation from cubic to monoclinic occurs at a low cooling rate. Impedance spectroscopy measurements under different atmospheres (dry and wet N2 and 5% H2−Ar) show that all materials exhibit mixed proton−electronic conductivity. The n-type electronic conductivity is attributed to Mo6+ reduction and increases for those phases with lower lanthanum content, i.e., for quenched samples, from 5 mS cm−1 for La5.4MoO11.1 to 9.5 mS cm−1 for La4MoO9 at 700 °C in very reducing and wet conditions, which are significantly better than the values published to date for mixed lanthanum tungstates/ molybdates. This makes these materials potential candidates for hydrogen separation membranes. | es_ES |
dc.language.iso | eng | es_ES |
dc.publisher | American Chemical Society | es_ES |
dc.rights | info:eu-repo/semantics/openAccess | es_ES |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | * |
dc.subject | Separación por membrana | es_ES |
dc.subject | Química organometálica | es_ES |
dc.subject.other | Hydrogen separation membrane | es_ES |
dc.subject.other | Lanthanum molybdate | es_ES |
dc.title | Unravelling Crystal Superstructures and Transformations in the La6−xMoO12−δ (0.6 ≤ x ≤ 3.0) Series: A System with Tailored Ionic/ Electronic Conductivity. | es_ES |
dc.type | info:eu-repo/semantics/article | es_ES |
dc.centro | Facultad de Ciencias | es_ES |
dc.identifier.doi | 10.1021/acs.chemmater.0c02673 | |
dc.rights.cc | Attribution-NonCommercial-NoDerivatives 4.0 Internacional | * |
dc.type.hasVersion | info:eu-repo/semantics/submittedVersion | es_ES |