Electronic structure of PbTiO3-based ferroelectric materials determined from LDA+U study

ORAL

Abstract

We perform a systematic theoretical study of the electronic structure of PbTiO$_3$ and related ferroelectric materials, using LDA+$U$ calculations. The effective on-site correlation terms $U$ for the localized electronic states of PbTiO$_3$ are determined with a linear-response method. Compared to the DFT- LDA method (where the band gap values are greatly underestimated), band gap values for PbTiO$_3$ obtained by LDA+$U$ calculations are much closer to the experimental results. Special focus has been paid to solid-state solutions formed by doping PbTiO$_3$ with a $d^8$ cation (Ni, Pd, Pt) and accompanying O vacancy, which have recently been proposed. We re-examine the dopant states of these materials, and also recalculate their electronic structures using the LDA+$U$ method. The improvement achieved with the LDA+$U$ method and comparison with experimental results will be presented.

*The authors acknowledge support from the DOE under Grant DE-FG02-07ER46431.

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Authors

  • Gaoyang Gou

    • The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323

  • Hiroyuki Takenaka

    • The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323

  • Joseph Bennett

    • The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323

  • Andrew Rappe

    • The Makineni Theoretical Laboratories, Deparment of Chemistry, University of Pennsylvania
    • The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323
    • University of Pennsylvania
    • The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA