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Evolution of ferroelectricity in ultrathin PbTiO3 films as revealed by electric double layer gating.

ABSTRACT: Ferroelectricity in ultrathin films is destabilized by depolarization field, which leads to the reduction of spontaneous polarization or domain formation. Here, thickness dependence of remnant polarization in PbTiO3 films is electrically revealed down to 2.6 nm by controlling the polarization direction with employing an electric double layer gating technique to suppress leakage current in ultrathin films. The remnant polarization for a 17 nm-thick film is similar to bulk value?~?60 ?C cm-2 and reduces to ~?20 ?C cm-2 for a 2.6 nm-thick film, whereas robust ferroelectricity is clearly observed in such ultrathin films. In-situ X-ray diffraction measurements under an external electric field reveal that the reduced tetragonality in ultrathin films is mostly recovered by cancelling out the depolarization field. Electric double layer gating technique is an excellent way for exploring physical properties in ultrathin ferroelectric films.

SUBMITTER: Nishino R

PROVIDER: S-EPMC7331690 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

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Evolution of ferroelectricity in ultrathin PbTiO3 films as revealed by electric double layer gating.

Nishino Ryutaro R Fujita Takahiro C TC Kagawa Fumitaka F Kawasaki Masashi M

Scientific reports 20200702 1

Ferroelectricity in ultrathin films is destabilized by depolarization field, which leads to the reduction of spontaneous polarization or domain formation. Here, thickness dependence of remnant polarization in PbTiO3 films is electrically revealed down to 2.6 nm by controlling the polarization direction with employing an electric double layer gating technique to suppress leakage current in ultrathin films. The remnant polarization for a 17 nm-thick film is similar to bulk value ~ 60 μC ...[more]

PMID: 32616739

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