Abstract
Hf0.5Zr0.5O2 emerges as a promising candidate for next-generation ferroelectric memories and transistors. However, the intrinsic nature of its ferroelectricity remains a subject of debate, primarily stemming from challenges in the precise characterization of nanoscale polycrystallinity and multiphase coexistence. Here, we investigate substrate-free Hf0.5Zr0.5O2 films using multislice electron ptychography, achieving a resolution of 25 picometers with capabilities for oxygen imaging, depth resolution, and vacancy quantification. Precise measurements reveal that the polarization displacement in ferroelectric phase is ∼56 ± 6 picometers (corresponding to a polarization ∼34 ± 4 μC/cm2). We further identify significant polarization suppression near grain boundaries, while there is negligible change in the 180° neutral domain walls. Furthermore, we demonstrate the existence of the 180° head-to-head charged domain wall in Hf0.5Zr0.5O2, which is confined within a single unit cell layer. At such a charged domain wall, the atomic displacement is reduced to ∼4 picometers, with oxygen vacancies accumulating up to 20%. Notably, the polar layers neighboring the 180º head-to-head charged domain wall remain unchanged. The precise determination of these structural features with ultra-high spatial resolution offers critical information for optimizing and designing new hafnium-based ferroelectric devices.
Data availability
The 4D-STEM data presented in this study are available in Zenodo https://doi.org/10.5281/zenodo.18373896.
Code availability
The code for MEP is available Zenodo https://doi.org/10.5281/zenodo.18373896.
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Acknowledgements
This work was supported by the National Natural Science Foundation of China (52125307 to P.G., 12222414 to C.G., 12504198 to J.D.) and the open research fund of Song-shan Lake Materials Laboratory (2022SLABFK03). P.G. acknowledges the support from the New Cornerstone Science Foundation through the XPLORER PRIZE. We acknowledge Electron Microscopy Laboratory of Peking University for the use of electron microscopes and High-performance Computing Platform of Peking University for providing computational resources. We acknowledge the assistance of Prof. Zhen Chen from Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China; We thank the discussion of Yi Jiang from the Advanced Photon Source, Argonne National Laboratory, USA.
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P.G. conceived the project. X.Y.G. performed the ptychographic experiments, reconstruction and data analyses with the assistance of B.H., R.L.M., R.C.S., R.X.Z., J.B.L., T.W., and J.D.L.; X.W.Z. performed the STEM-EELS experiment and analysis. Z.H.L., K.J.J., and C.G. prepared the HZO sample. X.Y.G. wrote the manuscript under the direction of J.D.L. and P.G.; All the authors contributed to this work through useful discussion and/or comments to the manuscript.
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Gao, X., Liu, Z., Han, B. et al. Precise structure and polarization determination of Hf0.5Zr0.5O2 with electron ptychography. Nat Commun (2026). https://doi.org/10.1038/s41467-026-69514-w
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DOI: https://doi.org/10.1038/s41467-026-69514-w
