Complex structural ordering of the oxygen deficiency in La0.5Ca2.5Mn2O7−δ Ruddlesden–Popper phases
| Autor: | José Luis Martínez, Daniel González-Merchante, Raquel Cortés-Gil, E. Matesanz, José M. González-Calbet, Jose M. Alonso, Jacobo Santamaria, M. Luisa Ruiz-González, Alberto Rivera-Calzada |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Neutron diffraction chemistry.chemical_element 02 engineering and technology Manganese 01 natural sciences Biochemistry Inorganic Chemistry Structural Biology Oxidation state 0103 physical sciences Scanning transmission electron microscopy Antiferromagnetism General Materials Science Physical and Theoretical Chemistry Spectroscopy 010302 applied physics Física de materiales 021001 nanoscience & nanotechnology Condensed Matter Physics Crystallography chemistry Electron diffraction Ferromagnetism Física del estado sólido 0210 nano-technology |
| Zdroj: | E-Prints Complutense: Archivo Institucional de la UCM Universidad Complutense de Madrid E-Prints Complutense. Archivo Institucional de la UCM instname |
| ISSN: | 2053-2733 |
| DOI: | 10.1107/s2053273319006089 |
| Popis: | Ruddlesden–Popper oxides, (AO)(ABO3) n , occupy a prominent place in the landscape of materials research because of their intriguing potential applications. Compositional modifications to the cation sublattices, A or B, have been explored in order to achieve enhanced functionalities. However, changes to the anionic sublattice have been much less explored. In this work, new oxygen-deficient manganese Ruddlesden–Popper-related phases, La0.5Ca2.5Mn2O6.5 and La0.5Ca2.5Mn2O6.25, have been synthesized by controlled reduction of the fully oxidized n = 2 term La0.5Ca2.5Mn2O7. A complete structural and compositional characterization, by means of neutron diffraction, electron diffraction and atomically resolved scanning transmission electron microscopy and electron energy-loss spectroscopy techniques, allows the proposition of a topotactic reduction pathway through preferential oxygen removal in the [MnO2] layers along [031] and [0{\bar 1}3] directions. The gradual decrease of the Mn oxidation state, accommodated by short-range ordering of anionic vacancies, reasonably explains the breaking of ferromagnetic interactions reinforcing the emergence of antiferromagnetic ones. Additional short-range order–disorder phenomena of La and Ca cations have been detected in the reduced La0.5Ca2.5Mn2O7−δ, as previously reported in the parent compound. |
| Databáze: | OpenAIRE |
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