The Mystery behind Dynamic Charge Disproportionation in BaBiO3

Autor:	Sumit Sarkar, Ram Janay Choudhary, D. M. Phase, Rajamani Raghunathan, Sourav Chowdhury
Rok vydání:	2021
Předmět:	X-ray spectroscopy Materials science Mechanical Engineering Bioengineering Disproportionation Molecular orbital theory Charge (physics) General Chemistry Condensed Matter Physics Octahedron Chemical physics General Materials Science Molecular orbital Density functional theory Perovskite (structure)
Zdroj:	Nano Letters. 21:8433-8438
ISSN:	1530-6992 1530-6984
DOI:	10.1021/acs.nanolett.1c03103
Popis:	BaBiO3(BBO) is known to be a valence-skipping perovskite, which avoids the metallic state through charge disproportionation (CD), the mechanism of which is still unresolved. A novel mechanism for CD is presented here in the covalent limit using a molecular orbital (MO) picture under two scenarios: (case i) Bi 6sp-O 2p and (case ii) Bi 6p-O 2p hybridizations that favor 5+ and 3+ states, respectively. The proposed model is further validated by using a combinatorial approach of X-ray spectroscopic experiments and first-principle calculations. The bulk X-ray photoemission spectrum reveals that, at room temperature, the CD is dynamic in nature, whereas, at 200 K, it approaches a quasi-static limit. Under compressive strain, the octahedral breathing mode is damped and drives the system to a quasi-static limit even at room temperature, giving rise to asymmetric CD.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::77fc31023539dae753742fe1664ec30a https://doi.org/10.1021/acs.nanolett.1c03103 Zobrazit plný text záznamu