Year: 2026
Type: article
Abstract: ABSTRACT Ferroelectricity in Hf 0.5 Zr 0.5 O 2 (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 0.67 Sr 0.33 MnO 3‐δ (LSMO), yttria‐stabilized ZrO 2‐δ (YSZ), and Gd‐doped CeO 2‐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.
Source: Advanced Functional Materials
Authors: Achilles Bergne, Denis Alikin, Milica Vasiljevic, Victor B. Tinti, Javier Zamudio‐García, Leonardo Soares de Oliveira, Megan Landberg, Dimitrios Koukoulis, Huaiyu Chen, Jesper Wallentin, David Marrero‐López, Astri Bjørnetun Haugen, Sizhao Huang, Dennis Christensen, Nini Pryds, Alexander Tselev, Andrei Kholkin, Vincenzo Esposito
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,790
Funders: European Commission, VINNOVA, Svenska Forskningsrådet Formas, Vetenskapsrådet, Danmarks Frie Forskningsfond, Ministério da Ciência, Tecnologia e Ensino Superior, Danmarks Frie Forskningsfond, Centro de Investigação em Materiais Cerâmicos e Compósitos, HORIZON EUROPE Framework Programme, Fundação para a Ciência e a Tecnologia, Horizon 2020
Awards: G1918496035, G2016314180, G208125138, G2268415616, G2343145294, G2862919931, G3144760282, G317939215, G3283876815, G3292045690, G3728818118, G4046065984, G404710190, G4116030365, G4317831669, G434337789, CICECO-Instituto de Materiais de Aveiro, G5096929151, MAX IV operations – Formas, G5224014036, G5229471624, CICECO – Instituto de Materiais de Aveiro, G594270511, Heterostructured metal halide perovskite nanowires, G6399485551, G6410266313, G6997658380, LOW-DIMENSIONAL FERROELECTRICS FOR ADVANCED ELECTRONIC AND BIOMEDICAL DEVICES, G712881263, G7403097962, 2D-ferroelectric materials and heterostructures for the photoelectrochemical water splitting, Unveiling Nano- and Mesoscopic-Scales Properties and Processes in Ferroic, Low-Dimensional, and Energy Materials, G8187247187, G8222313181, MAX IV operations 2019-2021, G8367945838, G8428786692, G8615870599
OpenAlex ID: W7129010287