First-principles study of ferroelectric charge-disproportionated phases in the cation-ordered La<sub>1/3</sub>Sr<sub>2/3</sub>FeO<sub>3</sub>

ORAL

Abstract

We investigate the structure and electronic properties of A-site cation ordered La1/3Sr2/3FeO3 using density functional theory plus Hubbard U corrections (DFT+U). A structure with A-site cation ordering, consisting of (111) planes of La and Sr ions with uniform separation, is considered. We find that depending on the charge ordering patterns, both centrosymmetric and ferroelectric phases exhibit charge disproportionation, with energy difference less than 1 meV per formula unit. The polar phase is induced by the symmetry breaking from A-site cation ordering combined with charge ordering, giving rise to sizable polarization of about 19 μC/cm2 mainly originating from electron transfer between Fe ions. We identify a possible insulating switching path, suggesting that the polar state could be induced by applied electric field, and, depending on the switching process, a ferroelectric hysteresis loop could be observed.

*This work supported by the Department of Energy.

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Presenters

  • Se Young Park

    • University of California Berkeley
    • Physics, University of California, Berkeley

Authors

  • Se Young Park

    • University of California Berkeley
    • Physics, University of California, Berkeley

  • Karin Rabe

    • Rutgers University
    • Physics and Astronomy, Rutgers University

  • Jeffrey Neaton

    • Molecular Foundry, Lawrence Berkeley National Laboratory; Department of Physics, University of California, Berkeley; Kavli Energy Nanosciences Institute at Berkeley
    • Physics, University of California, Berkeley; Lawrence Berkeley National Laboratory
    • Department of Physics, University of California
    • Univ of California - Berkeley
    • Lawrence Berkeley Natl Lab
    • Materials Science Division, Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Lab
    • Physics, University of California, Berkeley
    • Department of Physics UCB; Molecular Foundry LBNL; Kavli ENSI
    • Lawrence Berkeley National Laboratory
    • Department of Physics, Univ of California - Berkeley
    • Lawrence Berkeley National Lab and University of California - Berkeley