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Free keywords:
Charge transfer; Electronic structure; Lanthanum compounds; Nickel; Photoelectron spectroscopy; Charge disproportionation; Charge-transfer satellites; Density wave transition; Electronic correlation; Electronic.structure; Hard X-ray photoemission spectroscopy; Ni valence; Spectra's; Spectral shapes; Spectral weight; Nickel compounds
Abstract:
We have investigated the electronic structure of La3Ni2O7-δ (δ≈0.07) by means of hard x-ray photoemission spectroscopy (HAXPES). Although the nominal Ni valence is close to +2.5, the Ni 2p HAXPES spectra show an absence of Ni2+/Ni3+ charge disproportionation. The Ni 2p spectral shape including the main peak and the charge-transfer satellite indicate that oxygen 2p holes are heavily involved in the transport properties. The spectral weight suppression at the Fermi level indicates that the carriers of O 2p character (mixed with Ni 3d) are affected by electronic correlation which would be associated with the density wave transition and the superconductivity controlled by pressure. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.
