ケージ拘束原子変位によって反強誘電体の絶縁破壊耐性を向上（Cage-Confined Atomic Displacement Enhances Antiferroelectric Breakdown Resistance）

2026-09-28 中国科学院（CAS）

Illustration of the research: stable breakdown resistant molecular antiferroelectric triggered by confinement-dependent atomic displacement. (Image by FJIRSM)

＜関連情報＞

• https://english.cas.cn/newsroom/research-news/202609/t20260928_1201532.shtml
• https://onlinelibrary.wiley.com/doi/10.1002/anie.8019471

閉じ込め依存的な原子変位によって誘発される、安定かつ破壊耐性のある分子反強誘電体 Stable Breakdown-Resistant Molecular Antiferroelectric Triggered by Confinement-Dependent Atomic Displacement

Wenjing Li, Yu Ma, Yayu Yan, Yi Liu, Qingshun Fan, Liwei Tang, Qiaohong Li, Xiaobin Fu, Junhua Luo, Zhihua Sun
Angewandte Chemie International Edition  Published: 07 September 2026
DOI:https://doi.org/10.1002/anie.8019471

ABSTRACT

Molecular antiferroelectrics (AFEs) with antiparallel dipole alignment are promising for energy-storage capacitor applications. However, it is challenging to design new molecular AFEs with superior breakdown resistance, owing to the lack of knowledge on the atomic-level origin regarding AFE orders. Here, we present stable breakdown resistance in 2D perovskite AFE, (2‑MBA)₂CsPb₂Br₇ (2‑MBA = 2‑methylbutylammonium), involved with the confinement-dependent atomic displacement. It shows antiferroelectricity with a large spontaneous polarization of 5.0 µC/cm². Particularly, the cage‑confined Cs⁺ cations display atomic displacement to create stable antifatigue merits, including high breakdown field up to 175 kV/cm and the fatigue endurance beyond ∼10⁶ cycles, falling in the range of the highest level for molecular AFEs. Combination of energy barrier calculation and in situ solid-state NMR spectroscopy was used to reveal the crucial role of displacive dynamics. Contrary to order-disordering dynamics, it is the high energy barrier (E_a = 2.91 eV) of cage-confined Cs⁺ cation displacement that leads to the increase in Curie temperature (∼327 K) and forward coercive field (∼56.8 kV/cm). Such attributes allow for AFE switching under stronger external stimuli, thus endowing stable fatigue resistance even at higher breakdown fields. This work provides a feasible principle of delicately manipulating cage-confined dynamics to design new electric-ordered candidates.