蛍石型強誘電体の分極反転における原子の動きをリアルタイムに直接観察 ～ 次世代強誘電体デバイスに向けた材料開発の新たな設計指針 ～

2026-04-01 ファインセラミックスセンター

図１　蛍石型強誘電体にて直接観察された分極反転中の原子の動き

＜関連情報＞

• https://www.jfcc.or.jp/press/r26_1.html
• https://www.nature.com/articles/s41467-026-70593-y

蛍石型強誘電体における陽イオン依存性分極反転ダイナミクスの直接観察 Direct observation of cation-dependent polarisation switching dynamics in fluorite ferroelectrics

Kousuke Ooe,Yufan Shen,Kazuki Shitara,Rintaro Maki,Shunsuke Kobayashi,Yuichi Shimakawa,Daisuke Kan & Joanne Etheridge
Nature Communications  Published:30 March 2026
DOI:https://doi.org/10.1038/s41467-026-70593-y

Abstract

Fluorite ferroelectrics are exciting candidates for next-generation non-volatile memory devices because their unique ferroelectric mechanism, which arises from unconventional oxygen displacements, permits ferroelectricity with minimal thickness constraints. However, the polarisation switching mechanism remains the subject of intense debate due to a limited understanding of the atomic-scale dynamics which are extremely challenging to detect and measure. Here, we observe directly the polarisation switching pathways by visualising oxygen site dynamics in ZrO₂ and Hf_0.5Zr_0.5O₂ freestanding membranes using an advanced atomic-column imaging technique—optimum bright-field scanning transmission electron microscopy. We observe that the 180° and 90° polarisation pathways involve different nonpolar intermediate states with distinct spatial scales. Coupled with density functional theory, we also reveal how different cation species in fluorite oxides impact the accessible polarisation switching pathways. Our atomic-level insights into the polarisation switching dynamics open new avenues for the advanced engineering of fluorite ferroelectric materials and resulting memory devices.