Physical Review X 15, 021042 (2025)

Theoretical Lower Limit of Coercive Field in
Ferroelectric Hafnia

Jiyuan Yang1,*, Jing Wu1,*, Jingxuan Li2,*, Chao Zhou2, Yang Sun3, Zuhuang Chen2,†, and Shi Liu1,4,‡
1. Westlake University  |  2. Harbin Institute of Technology, Shenzhen
3. Xiamen University  |  4. Westlake Institute for Advanced Study

The Obstacle

The high coercive field (Ec) of hafnia-based ferroelectrics is a major barrier to application. The specific switching mechanisms—Nucleation-Limited Switching (NLS) vs. Kolmogorov-Avrami-Ishibashi (KAl) domain-wall motion—have remained elusive.

Methodology

We developed a deep-learning-assisted multiscale approach, incorporating atomistic insights into the critical nucleus. This allows us to predict both NLS-type and KAl-type coercive fields with high accuracy.

Key Findings

  • Origin of giant Ec : High coercive fields in ultrathin films arise from geometry confinement, forcing the system into the NLS mechanism.
  • Theoretical Limit: We predict the lower limit for KAl-type Ec is drastically lower, arising from mobile domain walls.
  • Experimental Proof: Achieved low Ec (1MV/cm) in 60 nm superlattices by activating KAl-type switching.
0.1 MV/cm THEORETICAL LOWER LIMIT (KAI-TYPE)