Exploring Topochemical Oxidation Reactions for Reversible Tuning of Thermal Conductivity in Perovskite Fe Oxides
We present a study on the reversibility of thermal conductivity in iron oxides through topochemical oxygen exchange between brownmillerite (BM) (Ca,Sr)FeO2.5 and perovskite (PV) (Ca,Sr)FeO3.0. By using different oxidation methods, including gas phase (O2/O3), liquid phase (NaOCl in H2O), and solid e...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Santiago de Compostela (USC) |
| Repositorio: | Minerva. Repositorio Institucional de la Universidad de Santiago de Compostela |
| Idioma: | inglés |
| OAI Identifier: | oai:minerva.usc.gal:10347/38157 |
| Acceso en línea: | https://hdl.handle.net/10347/38157 |
| Access Level: | acceso abierto |
| Palabra clave: | Oxidation Oxides Oxygen Photovoltaics Thin Films 2307 Química física |
| Sumario: | We present a study on the reversibility of thermal conductivity in iron oxides through topochemical oxygen exchange between brownmillerite (BM) (Ca,Sr)FeO2.5 and perovskite (PV) (Ca,Sr)FeO3.0. By using different oxidation methods, including gas phase (O2/O3), liquid phase (NaOCl in H2O), and solid electrolyte (Y2O3:ZrO2), we demonstrate that the oxidation pathway has a critical influence on the reversibility of the ionic-exchange process. Cyclic oxidation and reduction using O2/O3 or NaOCl lead to an important accumulation of structural defects, undermining the reversibility of thermal conductivity. In the case of wet oxidation, we demonstrate an inherent tendency of negative charge-transfer oxides toward amorphization and elucidate the origin of this effect. Conversely, the electrochemical injection of the O2– ions via a Y2O3:ZrO2 solid electrolyte reduces structural damage significantly, enhancing both reversibility and durability. This study underscores the importance of selecting appropriate topochemical oxygen exchange methods to maintain structural integrity and optimize functional performance in oxide-based tunable devices. |
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