Local Ordering, Distortion, and Redox Activity in (La0.75Sr0.25)(Mn0.25Fe0.25Co0.25Al0.25)O3 Investigated by a Computational Workflow for Compositionally Complex Perovskite Oxides

Local Ordering, Distortion, and Redox Activity in (La0.75Sr0.25)(Mn0.25Fe0.25Co0.25Al0.25)O3 Investigated by a Computational Workflow for Compositionally Complex Perovskite Oxides

© 2024 The Authors. Published by American Chemical Society.

Bibliographische Detailangaben
Veröffentlicht in:Chemistry of materials : a publication of the American Chemical Society. - 1998. - 36(2024), 10 vom: 28. Mai, Seite 4990-5001
1. Verfasser: Xu, Boyuan (VerfasserIn)
Weitere Verfasser: Park, Jiyun, Zhang, Dawei, De Santiago, Héctor A, Li, Wei, Liu, Xingbo, Luo, Jian, Lany, Stephan, Qi, Yue
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2024
Zugriff auf das übergeordnete Werk:Chemistry of materials : a publication of the American Chemical Society
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:© 2024 The Authors. Published by American Chemical Society.
Mixing multiple cations can result in a significant configurational entropy, offer a new compositional space with vast tunability, and introduce new computational challenges. For applications such as the two-step solar thermochemical hydrogen (STCH) generation techniques, we demonstrate that using density functional theory (DFT) combined with Metropolis Monte Carlo method (DFT-MC) can efficiently sample the possible cation configurations in compositionally complex perovskite oxide (CCPO) materials, with (La0.75Sr0.25)(Mn0.25Fe0.25Co0.25Al0.25)O3 as an example. In the presence of oxygen vacancies (VO), DFT-MC simulations reveal a significant increase of the local site preference of the cations (short-range ordering), compared to a more random mixing without VO. Co is found to be the redox-active element and the VO is the preferentially generated next to Co due to the stretched Co-O bonds. A clear definition of the vacancy formation energy (Evf) is proposed for CCPO in an ensemble of structures evolved in parallel from independent DFT-MC paths. By combining the distribution of Evf with VO interactions into a statistical model, the oxygen nonstoichiometry (δ), under the STCH thermal reduction and oxidation conditions, is predicted and compared with the experiments. Similar to the experiments, the predicted δ can be used to extract the enthalpy and entropy of reduction using the van't Hoff method, providing direct comparisons with the experimental results. This procedure provides a full predictive workflow for using DFT-MC to obtain possible local ordering or fully random structures, understand the redox activity of each element, and predict the thermodynamic properties of CCPOs, for computational screening and design of these CCPO materials at STCH conditions
Beschreibung:Date Revised 04.06.2024
published: Electronic-eCollection
Citation Status PubMed-not-MEDLINE
ISSN:0897-4756
DOI:10.1021/acs.chemmater.3c03038