Symmetry selective oxygen orbital polarization in spinel Al<sub>2</sub>O<sub>3</sub> films

POSTER

Abstract

Orbital polarization is common for the 3d orbitals of cations as a result of strain, symmetry breaking, or charge transfer, but very rare for 2p orbitals of simple anions. Here, we report a symmetry-selective measurement of orbital polarization for O 2p orbitals in γ-Al2O3/SrTiO3 thin films via linearly polarized X-ray absorption spectroscopy (XAS) at the O K-edge. The O 2p orbitals with octahedral coordination exhibit a large subband splitting exceeding ~ 0.35 eV, while those with tetrahedral coordination show a very weak orbital polarization. These results pave a new way to engineer band structure and quantum states of functional oxide materials via local symmetry effects on anion orbitals.

*National Natural Science Foundation of China (No:11874058)

Presenters

  • Ruyi Zhang

    • Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences
    • Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences.

Authors

  • Ruyi Zhang

    • Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences
    • Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences.

  • Yang Song

    • Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences.

  • Yanwei Cao

    • Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences
    • Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences.
    • Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences
    • Chinese Academy of Science