Persisting of Polar Distortion with Electron Doping in Lone-Pair Driven Ferroelectrics

Abstract

Free electrons can screen out long-range Coulomb interaction and destroy the polar distortion in some ferroelectric materials, whereas the coexistence of polar distortion and metallicity were found in several non-central-symmetric metals (NCSMs). Therefore, the mechanisms and designing of NCSMs have attracted great interests. In this work, by first-principles calculation, we found the polar distortion in the lone-pair driven ferroelectric material PbTiO${}_3$ can not only persist, but also increase with electron doping. We further analyzed the mechanisms of the persisting of the polar distortion. We found that the Ti site polar instability is suppressed but the Pb site polar instability is intact with the electron doping. The Pb-site instability is due to the lone-pair mechanism which can be viewed as a pseudo-Jahn-Teller effect, a mix of the ground state and the excited state by ion displacement from the central symmetric position. The lone-pair mechanism is not strongly affected by the electron doping because neither the ground state or the excited state involved is at the Fermi energy. The enhancement of the polar distortion is related to the increasing of the Ti ion size by doping. These results show the lone-pair stereoactive ions can be used in designing NCSMs.

9 pages, 7 figures

References in corpus (9)

• Origin of magnetoelectric behavior in BiFeO${}_3$
• A ferroelectric-like structural transition in a metal
• `Ferroelectric' Metals Reexamined: Fundamental Mechanisms and Design Considerations for New Materials
• Ferroelectric Instability under Screened Coulomb Interactions
• Local structural origins of the distinct electronic properties of Nb-substituted SrTiO${}_3$ and BaTi$O_3$
• Dual nature of the ferroelectric and metallic state in LiOsO${}_3$
• Metallic ferroelectricity induced by anisotropic unscreened coulomb interaction in LiOsO3
• Stabilization of highly polar BiFeO${}_3$-like structure: a new interface design route for enhanced ferroelectricity in artificial perovskite superlattices
• Evolution of the electronic and lattice structure with carrier injection in BiFeO${}_3$

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• Polar Metals Taxonomy for Materials Classification and Discovery
• Probing ferroelectricity in highly conducting materials through their elastic response: persistence of ferroelectricity in metallic BaTiO3-d
• Multiferroic metal-PbNb${}_{0.12}$Ti${}_{0.88}$O${}_{3-\delta }$ films on Nb-doped STO
• Covalency driven modulation of paramagnetism and development of lone pair ferroelectricity in multiferroic Pb${}_3$TeMn${}_3$P${}_2$O${}_{14}$
• Quantum fluctuation of ferroelectric order in polar metals
• Phonon anomalies within the polar charge density wave phase of the structurally chiral superconductor Mo${}_3$Al${}_2$C
• Magnetoresistance in Metallic Ferroelectrics
• Two-dimensional metallic ferroelectricity in PbTe monolayer by electrostatic doping