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Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy

Local distortions in perovskites can be induced by cation displacements and/or by the tilting and rotating of cation–anion octahedra. Both phenomena have been subject to intense investigations over many years. However, there are still controversies in the results obtained from experimental technique...

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Autores principales: Bakradze, Georgijs, Kuzmin, Alexei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9654710/
https://www.ncbi.nlm.nih.gov/pubmed/36363212
http://dx.doi.org/10.3390/ma15217619
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author Bakradze, Georgijs
Kuzmin, Alexei
author_facet Bakradze, Georgijs
Kuzmin, Alexei
author_sort Bakradze, Georgijs
collection PubMed
description Local distortions in perovskites can be induced by cation displacements and/or by the tilting and rotating of cation–anion octahedra. Both phenomena have been subject to intense investigations over many years. However, there are still controversies in the results obtained from experimental techniques that are sensitive to long-range order (X-ray, neutron, or electron diffraction) and those sensitive to short-range order (X-ray absorption spectroscopy). In this study, we probed the details of the local environment in AMoO(3) perovskites (A = Ca, Sr, Ba) using extended X-ray absorption fine structure (EXAFS) in a wide temperature range (10–300 K). An advanced analysis of the EXAFS spectra within the multiple-scattering formalism using the reverse Monte Carlo method enhanced by an evolutionary algorithm allowed us (i) to extract detailed information on metal–oxygen and metal–metal radial distribution functions, and metal–oxygen–metal and oxygen–metal–oxygen bond angle distribution functions, and (ii) to perform polyhedral analysis. The obtained results demonstrate the strong sensitivity of the EXAFS spectra to the tilting of [MoO(6)] octahedra induced by the differences in the sizes of alkaline earth metal cations (Ca(2+), Sr(2+), and Ba(2+)).
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spelling pubmed-96547102022-11-15 Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy Bakradze, Georgijs Kuzmin, Alexei Materials (Basel) Article Local distortions in perovskites can be induced by cation displacements and/or by the tilting and rotating of cation–anion octahedra. Both phenomena have been subject to intense investigations over many years. However, there are still controversies in the results obtained from experimental techniques that are sensitive to long-range order (X-ray, neutron, or electron diffraction) and those sensitive to short-range order (X-ray absorption spectroscopy). In this study, we probed the details of the local environment in AMoO(3) perovskites (A = Ca, Sr, Ba) using extended X-ray absorption fine structure (EXAFS) in a wide temperature range (10–300 K). An advanced analysis of the EXAFS spectra within the multiple-scattering formalism using the reverse Monte Carlo method enhanced by an evolutionary algorithm allowed us (i) to extract detailed information on metal–oxygen and metal–metal radial distribution functions, and metal–oxygen–metal and oxygen–metal–oxygen bond angle distribution functions, and (ii) to perform polyhedral analysis. The obtained results demonstrate the strong sensitivity of the EXAFS spectra to the tilting of [MoO(6)] octahedra induced by the differences in the sizes of alkaline earth metal cations (Ca(2+), Sr(2+), and Ba(2+)). MDPI 2022-10-30 /pmc/articles/PMC9654710/ /pubmed/36363212 http://dx.doi.org/10.3390/ma15217619 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Bakradze, Georgijs
Kuzmin, Alexei
Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy
title Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy
title_full Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy
title_fullStr Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy
title_full_unstemmed Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy
title_short Octahedral Tilting in Homologous Perovskite Series CaMoO3-SrMoO3-BaMoO3 Probed by Temperature-Dependent EXAFS Spectroscopy
title_sort octahedral tilting in homologous perovskite series camoo3-srmoo3-bamoo3 probed by temperature-dependent exafs spectroscopy
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9654710/
https://www.ncbi.nlm.nih.gov/pubmed/36363212
http://dx.doi.org/10.3390/ma15217619
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