Abstract:
The electromechanical properties of hafnium zirconium oxide fluorite (Hf0.5Zr0.5O2, HZO) remain largely unexplored despite its widespread use as a ferroelectric in CMOS-compatible devices. Here, we demonstrate that electrostriction-driven phase instability enables a giant pseudo-piezoelectric response in epitaxial HZO thin films. Above a critical field of 24 kilovolts per centimeter, field-induced transitions between nonpolar and polar phases activate an extrinsic piezoelectric response of ~1000 picometers per volt and bias-stabilized pseudo-piezoelectric strains exceeding 10,000 picometers per volt. This behavior arises from a combination of large electrostriction (M = 1 × 10−14 square meters per square volt), ferroelastic softness, and structural reconfiguration, rather than intrinsic polarization switching. Multimodal characterization combining interferometry, diffraction methods, scanning probe microscopy, and first-principles modeling confirms the coupling between strain and metastable phase dynamics. These findings reveal a previously unrecognized mechanism for functional strain generation in fluorite oxides, positioning HZO as a versatile platform for strain-engineered actuators, adaptive metasurfaces, and reconfigurable nanoelectromechanical systems.
Title: Electrostriction-driven phase instability enables giant pseudo-piezoelectricity in Hf0.5Zr0.5O2X
Authors: A. Bergne, M. Vasiljevic, D. Alikin, V. Buratto Tinti, L. Oliveira, M. O. Landberg Hill, H. Chen, J. Wallentin, D. Jennings, W. Rheinheimer, H. Bruus, M. Grønborg, D. Koukoulis, A.A. Morin-Martinez, J. Zamudio-García, I. Eligio Castelli, R. Ignatāns, A. Kholkin, D. Valbjørn Christensen, N. Pryds, V. Esposito
Reference: Science Advances, 12, 26, 2026
