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arXiv · 1802.07464

Meta-screening and permanence of polar distortion in metallized ferroelectrics

Hong Jian Zhao·Alessio Filippetti·Carlos Escorihuela-Sayalero·Pietro Delugas·Enric Canadell·Laurent Bellaiche·Vincenzo Fiorentini·Jorge Iniguez
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Abstract

Ferroelectric materials are characterized by a spontaneous polar distortion. The behavior of such distortions in the presence of free charge is the key to the physics of metallized ferroelectrics in particular, and of structurally-polar metals more generally. Using first-principles simulations, here we show that a polar distortion resists metallization and the attendant suppression of long-range dipolar interactions in the vast majority of a sample of 11 representative ferroelectrics. We identify a meta-screening effect, occurring in the doped compounds as a consequence of the charge rearrangements associated to electrostatic screening, as the main factor determining the survival of a non-centrosymmetric phase. Our findings advance greatly our understanding of the essentials of structurally-polar metals, and offer guidelines on the behavior of ferroelectrics upon field-effect charge injection or proximity to conductive device elements.

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Hong Jian Zhao, Alessio Filippetti, Carlos Escorihuela-Sayalero, Pietro Delugas, Enric Canadell, Laurent Bellaiche, Vincenzo Fiorentini, Jorge Iniguez. 2018-02-21. Meta-screening and permanence of polar distortion in metallized ferroelectrics. https://doi.org/10.1103/physrevb.97.054107

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