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Electro-Chemo-Mechanical Coupling in Hf0.5Zr0.5O2 Ferroionic Heterostructures

Bergne, Achilles ; Alikin, Denis ; Vasiljevic, Milica ; B. Tinti, Victor ; Zamudio-García, Javier ; Soares de Oliveira, Leonardo LU orcid ; Landberg, Megan LU ; Koukoulis, Dimitrios ; Chen, Huaiyu LU and Wallentin, Jesper LU , et al. (2026) In Advanced Functional Materials
Abstract

Ferroelectricity in Hf0.5Zr0.5O2 (HZO) originates from a polymorphic landscape where the metastable orthorhombic phase competes with monoclinic and tetragonal forms, making functional properties highly sensitive to structural instability. Recent strategies have exploited ionic-vacancy mechanisms, either through redox interactions with the environment or by employing ferroionic heterostructures, to enhance ferroelectric performance. Here, we embrace the ferroionic heterostructure approach and demonstrate that dynamic oxygen-vacancy exchange at epitaxial junctions produces an active interplay between ferroelectric and ionic layers. Epitaxial heterostructures with... (More)

Ferroelectricity in Hf0.5Zr0.5O2 (HZO) originates from a polymorphic landscape where the metastable orthorhombic phase competes with monoclinic and tetragonal forms, making functional properties highly sensitive to structural instability. Recent strategies have exploited ionic-vacancy mechanisms, either through redox interactions with the environment or by employing ferroionic heterostructures, to enhance ferroelectric performance. Here, we embrace the ferroionic heterostructure approach and demonstrate that dynamic oxygen-vacancy exchange at epitaxial junctions produces an active interplay between ferroelectric and ionic layers. Epitaxial heterostructures with La0.67Sr0.33MnO3-δ (LSMO), yttria-stabilized ZrO2-δ (YSZ), and Gd-doped CeO2-δ (CGO) reveal coupled electro-chemo-mechanical responses, including ferroelectric diode characteristics and subtle lattice distortions. Epitaxial fluorite-fluorite interfaces act as vacancy-exchange gates that bias polymorphism, enhance polarization, strengthen piezoelectric response, and suppress leakage, in contrast to the electronically dominated perovskite-fluorite junctions. These findings show that ferroionic heterostructures host reciprocal vacancy-driven dynamics, establishing them as a platform for defect-programmable ferroelectricity and tunable functionality in hafnia-based oxides.

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organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
defect engineering, dynamic tuning, epitaxial heterostructures, ferroionic interfaces, hafnia ferroelectrics, oxygen vacancies, polymorphism control
in
Advanced Functional Materials
pages
11 pages
publisher
Wiley-Blackwell
external identifiers
  • scopus:105030201988
ISSN
1616-301X
DOI
10.1002/adfm.202530176
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2026 The Author(s). Advanced Functional Materials published by Wiley-VCH GmbH.
id
e8df4a1c-b960-47bd-9b7d-8c46da8b6807
date added to LUP
2026-02-23 12:40:19
date last changed
2026-02-24 10:02:55
@article{e8df4a1c-b960-47bd-9b7d-8c46da8b6807,
  abstract     = {{<p>Ferroelectricity in Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> (HZO) originates from a polymorphic landscape where the metastable orthorhombic phase competes with monoclinic and tetragonal forms, making functional properties highly sensitive to structural instability. Recent strategies have exploited ionic-vacancy mechanisms, either through redox interactions with the environment or by employing ferroionic heterostructures, to enhance ferroelectric performance. Here, we embrace the ferroionic heterostructure approach and demonstrate that dynamic oxygen-vacancy exchange at epitaxial junctions produces an active interplay between ferroelectric and ionic layers. Epitaxial heterostructures with La<sub>0.67</sub>Sr<sub>0.33</sub>MnO<sub>3-δ</sub> (LSMO), yttria-stabilized ZrO<sub>2-δ</sub> (YSZ), and Gd-doped CeO<sub>2-δ</sub> (CGO) reveal coupled electro-chemo-mechanical responses, including ferroelectric diode characteristics and subtle lattice distortions. Epitaxial fluorite-fluorite interfaces act as vacancy-exchange gates that bias polymorphism, enhance polarization, strengthen piezoelectric response, and suppress leakage, in contrast to the electronically dominated perovskite-fluorite junctions. These findings show that ferroionic heterostructures host reciprocal vacancy-driven dynamics, establishing them as a platform for defect-programmable ferroelectricity and tunable functionality in hafnia-based oxides.</p>}},
  author       = {{Bergne, Achilles and Alikin, Denis and Vasiljevic, Milica and B. Tinti, Victor and Zamudio-García, Javier and Soares de Oliveira, Leonardo and Landberg, Megan and Koukoulis, Dimitrios and Chen, Huaiyu and Wallentin, Jesper and Marrero-López, David and Bjørnetun Haugen, Astri and Huang, Sizhao and Christensen, Dennis and Pryds, Nini and Tselev, Alexander and Kholkin, Andrei and Esposito, Vincenzo}},
  issn         = {{1616-301X}},
  keywords     = {{defect engineering; dynamic tuning; epitaxial heterostructures; ferroionic interfaces; hafnia ferroelectrics; oxygen vacancies; polymorphism control}},
  language     = {{eng}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Advanced Functional Materials}},
  title        = {{Electro-Chemo-Mechanical Coupling in Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> Ferroionic Heterostructures}},
  url          = {{http://dx.doi.org/10.1002/adfm.202530176}},
  doi          = {{10.1002/adfm.202530176}},
  year         = {{2026}},
}