Mechanical and Materials Engineering, Department of
Department of Mechanical and Materials Engineering: Faculty Publications
Ultrafast Dynamics of Ferroelectric Polarization of NbOI2 Captured with Femtosecond Electron Diffraction
ORCID IDs
Wang https://orcid.org/0000-0003-0869-7001
Hossain https://orcid.org/0000-0003-3539-6933
Li https://orcid.org/0000-0001-6408-642X
Xiong https://orcid.org/0000-0002-9412-4447
Le https://orcid.org/0009-0009-4768-5434
Fernandez-Ballester https://orcid.org/0000-0001-6956-5104
Hong https://orcid.org/0000-0002-7873-5774
Sinitskii https://orcid.org/0000-0002-8688-3451
Centurion https://orcid.org/0000-0002-5662-2293
Document Type
Article
Date of this Version
8-2025
Citation
Nature Communications (2025) 16: 8132
doi: 10.1038/s41467-025-63533-9
Abstract
Two-dimensional ferroelectric materials like NbOI2 have garnered significant interest, yet their temporal response and synergetic interaction with light remain underexplored. Previous studies on the polarization of oxide ferroelectrics have relied on time-resolved optical second harmonic generation or ultrafast X-ray scattering. Here, we probe the laser-induced polarization dynamics of NbOI2 nanocrystals using ultrafast transmission electron diffraction and deflectometry. The deflection of the electron pulses is directly sensitive to the changes in the polarization, while the diffraction signal captures the structural evolution. Excited with a UV laser pulse, the polarization of NbOI2 is initially suppressed for two picoseconds, then it recovers and overshoots, leading to a transiently enhanced polarization persisting for over 200 ps. This recovery coincides with coherent acoustic phonon generation, triggering a piezoresponse in the NbOI2 nanocrystals. Our results offer a new method for sensing the ferroelectric order parameter on femtosecond time scales.
Comments
Open access
License: CC BY-NC-ND 4.0 International