XAS signature of ferroelectricity in Croconic Acid

ORAL

Abstract

Molecular ferroelectrics (FE) based on ordering hydrogen bonds have potentially high electric polarization and ordering temperature compared with the conventional oxide FE materials. In particular, croconic acid (C5O5H2) has a FE polarization of 26 μC/cm2, in which the polar mode is strongly coupled to the intermolecular proton transfer. We applied X-ray absorption spectroscopy (XAS), a characterization technique that is sensitive to local structural and chemical properties, to probe the hydrogen bond structures of the croconic acid. First-principles simulations were used to interpret oxygen K-edge XAS features of croconic acid. The calculated XAS spectra semi-quantitatively agree with the three main experimental features at ~531.2 eV, 533.6 eV and 541.1 eV, respectively. The electron excitations in the two low-energy spectral features are found to be closely associated with the proton transfer, which gives rise to the FE polarization and can be recognized as a spectral signature of the FE in the croconic acid.

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Presenters

  • Fujie Tang

    Temple University

Authors

  • Fujie Tang

    Temple University

  • Pratikkumar H Dhuvad

    Temple University

  • Xuanyuan Jiang

    Department of Physics and Astronomy, University of Nebraska-Lincoln, University of Nebraska, Department of Physics and Astronomy, University of Nebraska - Lincoln, Physics, University of Nebraska Lincoln

  • Mehmet Topsakal

    Brookhaven National Laboratory, Center for Functional Nanomaterials, Columbia university

  • Deyu Lu

    Center for Functional Nanomaterials, Brookhaven National Laboratory, Brookhaven National Laboratory, Center for Functional Nanomaterials, Brookhaven National Laboratory

  • Xiaoshan Xu

    Department of Physics and Astronomy, University of Nebraska-Lincoln, University of Nebraska - Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, University of Nebraska, Department of Physics and Astronomy, Physics, University of Nebraska Lincoln

  • Xifan Wu

    Temple University, Physics, Temple University