| Autor: |
Raji, Aravind, Dong, Zhengang, Porée, Victor, Subedi, Alaska, Li, Xiaoyan, Mundet, Bernat, Varbaro, Lucia, Domínguez, Claribel, Hadjimichael, Marios, Feng, Bohan, Nicolaou, Alessandro, Rueff, Jean-Pascal, Li, Danfeng, Gloter, Alexandre |
| Rok vydání: |
2023 |
| Předmět: |
|
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1021/acsnano.3c07614 |
| Popis: |
The metal-hydride-based topochemical reduction process has produced novel thermodynamically unstable phases across various transition metal oxide series with unusual crystal structures and non-trivial ground states. Here, by such an oxygen (de-) intercalation method we synthesis a novel samarium nickelate with ordered nickel valences associated with tri-component coordination configurations. This structure, with a formula of Sm$_{9}$Ni$_{9}$O$_{22}$ as revealed by four-dimensional scanning transmission electron microscopy, emerges from the intricate planes of {303}$_{\text{pc}}$ ordered apical oxygen vacancies. X-ray spectroscopy measurements and ab-initio calculations show the coexistence of square-planar, pyramidal and octahedral Ni sites with mono-, bi- and tri-valences. It leads to an intense orbital polarization, charge-ordering, and a ground state with a strong electron localization marked by the disappearance of ligand-hole configuration at low-temperature. This new nickelate compound provides another example of previously inaccessible materials enabled by topotactic transformations and presents a unique platform where mixed Ni valence can give rise to exotic phenomena. |
| Databáze: |
arXiv |
| Externí odkaz: |
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