Electronic structure of CoO, Li-doped CoO, and LiCoO2

J van Elp*, JL Wieland, H Eskes, P Kuiper, G.A Sawatzky, F.M.F e Groot, T.S Turner

*Corresponding author for this work

    Research output: Contribution to journalArticleAcademicpeer-review

    611 Citations (Scopus)

    Abstract

    The electronic structure of Li(x)Co(1-x)O (0.01 less-than-or-equal-to x less-than-or-equal-to 0.2), LiCoO2, and Co3O4(1% Li) has been investigated using x-ray photoemission spectroscopy (XPS), bremsstrahlung isochromat spectroscopy (BIS), and x-ray-absorption spectroscopy. The experimental results are compared with model cluster calculations. We find that the CoO band gap is of an intermediate character, between Mott-Hubbard-like and charge-transfer-like. The first ionization state of CoO is therefore of strongly mixed Co 3d and O 2p character. Its local symmetry corresponds to 3T1g, similar to an intermediate-spin Co3+ state. For x less-than-or-equal-to 0.2 the local Co electronic structure is similar to that of CoO. However, LiCoO2 has a strongly reduced Co-O interatomic distance, resulting in a ligand field strong enough to stabilize a Co3+ low-spin ground state. LiCoO2 is an insulator with a gap of 2.7 eV. From a comparison of the XPS and BIS CoO spectra to the cluster calculations, we find values for U (= 5.3 eV), DELTA (= 5.5 eV), and (pd-sigma) (= 1.3 eV).

    Original languageEnglish
    Pages (from-to)6090-6103
    Number of pages14
    JournalPhysical Review. B: Condensed Matter and Materials Physics
    Volume44
    Issue number12
    DOIs
    Publication statusPublished - 15-Sept-1991

    Keywords

    • TRANSITION-METAL COMPOUNDS
    • X-RAY-ABSORPTION
    • PHOTOELECTRON-SPECTRA
    • NICKEL DIHALIDES
    • BAND-GAPS
    • PHOTOEMISSION
    • CU
    • SPECTROSCOPY
    • MONOXIDES
    • OXIDES

    Fingerprint

    Dive into the research topics of 'Electronic structure of CoO, Li-doped CoO, and LiCoO2'. Together they form a unique fingerprint.

    Cite this