RT Journal Article
T1 Structure and Mixed Proton–Electronic Conductivity in Pr and Nb-Substituted La5.4MoO12−δ Ceramics.
A1 Sánchez Caballero, Abraham
A1 Porras-Vázquez, José Manuel
A1 dos Santos-Gómez, Lucía
A1 Zamudio-García, Javier
A1 Infantes-Molina, Antonia
A1 Canales-Vázquez, J.
A1 Ramírez-Losilla, Enrique
A1 Marrero-López, David
K1 Polimorfismo (Cristalografía)
K1 Conductores eléctricos
K1 Materiales
AB Lanthanide molybdates are materials known for their mixed proton–ionic conductivity.This study investigates the effects of Pr content and Nb-doping on the crystalstructure and electrical properties of the La5.4−xPrxMo1−yNbyO12−δ (x = 0, 1.35, 2.7, 4.05,5.4; y = 0, 0.1) series. The research focuses on two primary objectives: (i) enhancing theelectronic conductivity through the use of Pr4+/Pr3+ redox pairs and (ii) increasing theionic conductivity through Nb5+ aliovalent doping. The materials were thoroughly characterizedby X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS),transmission and scanning electron microscopy (TEM and SEM), and complex impedancespectroscopy. The average crystal structure of the materials depended significantly onthe Pr content. In general, compositions with a higher Pr content crystallize in a cubicfluorite-type structure, whereas those with a lower Pr content stabilize a rhombohedralpolymorph. However, detailed TEM studies reveal a more complex local crystal structurecharacterized by nanodomains and incommensurate modulations. The highest conductivityvalues were observed in a N2 atmosphere for compositions with an elevated Prcontent, with values of 0.17 and 204.4 mS cm−1 for x = 0 and x = 5.4, respectively, at700 ◦C, which is attributed to electronic conduction mediated by the Pr4+/Pr3+ redox pair,as confirmed by XPS. These findings highlight the potential of tailored doping strategies tooptimize the conducting properties of lanthanide molybdates for specific high-temperatureelectrochemical applications.
PB MDPI
YR 2025
FD 2025-01-24
LK https://hdl.handle.net/10630/37981
UL https://hdl.handle.net/10630/37981
LA eng
NO Sánchez-Caballero, A.; Porras-Vázquez, J.M.; dos Santos-Gómez, L.; Zamudio-García, J.; Infantes-Molina, A.; Canales-Vázquez, J.; Losilla, E.R.; Marrero-López, D. Structure and Mixed Proton– Electronic Conductivity in Pr and Nb-Substituted La5.4MoO12−δ Ceramics. Materials 2025, 18, 529. https://doi.org/10.3390/ ma18030529
NO The authors acknowledge the research projects PID2021–126009OB-I00, PID2019-110249RBI00,and TED2021-129836B-I00 funded by Ministerio de Ciencia e Innovación (Spain) and “ERDF Away of making Europe” by the European Union. J.Z.-G. thanks the Technical University of Denmarkfor his Postdoctoral contract.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 23 abr 2026