Structure, electrical conductivity and oxygen transport properties of Ruddlesden–Popper phases Lnn+1NinO3n+1 (Ln = La, Pr and Nd; n = 1, 2 and 3)
| Autor: | Jia Song, Jean-Marc Bassat, De Ning, Henny J.M. Bouwmeester, Bernard A. Boukamp |
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| Přispěvatelé: | Inorganic Membranes, Inorganic Materials Science, Institute for Nanotechnology (MESA+), University of Twente [Netherlands], Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), CAS Key Laboratory of Materials for Energy Conversion, Southern University of Science and Technology of China (SUSTech), Institute of Energy and Climate Research: Materials Synthesis and Processing (IEK-1), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Financial support from the Dutch Technology Foundation (STW, now part of NWO, Project Nr. 15325) and the Chinese Scholarship Council (CSC 201406340102) are gratefully acknowledged. |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Lanthanide
Phase transition Materials science This article is licensed under a Creative Commons Attribution-NonCommercial 3 25:05 PM Analytical chemistry Oxide UT-Hybrid-D 02 engineering and technology Conductivity 010402 general chemistry 01 natural sciences chemistry.chemical_compound Electrical resistivity and conductivity General Materials Science Electronic band structure Valence (chemistry) Renewable Energy Sustainability and the Environment Oxygen transport [CHIM.MATE]Chemical Sciences/Material chemistry General Chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences chemistry Others 0 Unported Licence View Article Online 0210 nano-technology |
| Zdroj: | Journal of Materials Chemistry A, 8(42), 22206-22221. Royal Society of Chemistry Journal of Materials Chemistry A Journal of Materials Chemistry A, Royal Society of Chemistry, 2020, 8 (42), pp.22206-22221. ⟨10.1039/D0TA06731H⟩ |
| ISSN: | 2050-7488 |
| DOI: | 10.1039/D0TA06731H⟩ |
| Popis: | International audience; Layered Ruddlesden–Popper (RP) lanthanide nickelates, Lnn+1NinO3n+1 (Ln = La, Pr and Nd; n = 1, 2 and 3), are considered potential cathode materials in solid oxide fuel cells. In this study, the thermal evolution of the structure, oxygen nonstoichiometry, electrical conductivity and oxygen transport properties of La2NiO4+δ, Nd2NiO4+δ, La3Ni2O7−δ, La4Ni3O10−δ, Pr4Ni3O10−δ and Nd4Ni3O10−δ are investigated. Phase transitions involving a disruption of the cooperative tilting of the perovskite layers in the low-temperature structure thereby transforming it to a more symmetric structure are observed in several of the materials upon heating in air. Pr4Ni3O10−δ and Nd4Ni3O10−δ show no phase transition from room temperature up to 1000 °C. High density ceramics (>96%) are obtained after sintering at 1300 °C and (for n = 2 and n = 3 members) post-sintering annealing at reduced temperatures. Data for the electrical conductivity measurements on these specimens indicate itinerant behaviour of the charge carriers in the RP nickelates. The increase in p-type conductivity with the order n of the RP phase is interpreted as arising from the concomitant increase in the formal valence of Ni. The observations can be interpreted in terms of a simple energy band scheme, showing that electron holes are formed in the σx2−y2↑ band upon increasing the oxidation state of Ni. Electrical conductivity relaxation measurements reveal remarkable similarities between the surface exchange coefficients (kchem) of the different RP phases despite the differences in the order parameter n and the nature of the lanthanide ion. Calculation of the oxygen self-diffusion coefficients (Ds) from the experimental values of the chemical diffusion coefficients (Dchem), using the corresponding data of oxygen non-stoichiometry from thermogravimetry measurements, shows that these are strongly determined by the order parameter n. The value of Ds decreases almost one order of magnitude on going from the n = 1 members La2NiO4+δ and Nd2NiO4+δ to the n = 2 member La3Ni2O7−δ, and again one order of magnitude on going to the n = 3 members La4Ni3O10−δ, Pr4Ni3O10−δ and Nd4Ni3O10−δ. The results confirm that oxygen-ion transport in the investigated RP nickelates predominantly occurs via an interstitialcy mechanism within the rock-salt layer of the structures. |
| Databáze: | OpenAIRE |
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