NpjComput.Mater.：鐵電的180°極化翻轉：N和T路徑的機制！

海歸學者發起的公益學術平臺

分享資訊，整合資源

交流學術，偶爾風月

近年被發現的HfO₂基鐵電材料，具有與矽基半導體工藝相容的特點，並且在奈米尺度上能保持良好的鐵電性。因此，這類鐵電材料被認為是用於非易失性儲存器及相關電子裝置的重要候選材料。然而，除了HfO₂的鐵電亞穩相穩定機制外，其極化翻轉機制也是困擾人們的重要問題，從而給HfO₂基鐵電材料的可控設計及其儲存器可靠性與工藝穩定性的提升帶來了困難。

Fig. 1 | The eight 180° uniform polarization reversal pathways of Pca21 HfO2

來自湘潭大學材料科學與工程學院的鐵電薄膜與儲存器團隊，基於第一性原理彈性帶方法，在塊體和Ni/HfO₂/Ni異質結中研究了HfO₂的180°一致極化翻轉和電疇演化。研究結果較為系統地揭示了不同翻轉路徑的結構和能量演化規律，對HfO₂基材料鐵電性的理解具有重要意義。

Fig. 2 | The structural evolutions of uniform polarization reversal along a C:N, b C:N34ex, c S:N, and d S:T pathways in Ni/HfO₂/Ni heterostructures.

他們首先研究了正交HfO₂鐵電體的一致極化翻轉，發現在8種可能極化翻轉路徑中，O原子不跨Hf平面的極化翻轉模式(N路徑)具有最低的塊體翻轉勢壘；而在Ni/HfO₂/Ni異質結中，由於表面終斷的引入，即使伴隨著介面Ni-O鍵的形成和斷裂，O跨Hf平面的極化翻轉(T路徑)勢壘也被極大地抑制。隨後他們研究了HfO₂鐵電的電疇演化，發現由於引入高能的疇壁，N路徑的極化翻轉具有較高的形核勢壘和很低的疇壁遷移勢壘，而T路徑則具有較低的形核勢壘和較高的疇壁遷移勢壘；而在上述異質結中，T路徑的疇壁遷移勢壘被降低到與N路徑的相當。

Fig. 3 | The energy profiles (averaged to each u.c.) of uniformpolarization reversal in Ni/HfO2/Niheterostructures along a C:N, b C:N34ex, c S:N, and d S:T pathways

這些研究結果表明，在HfO₂中，N和T路徑的極化翻轉在適當的條件下都有可能發生，從而導致了HfO₂鐵電體極化翻轉性質的複雜性。該文近期發表於npj Computational Materials11：126(2025)，英文標題與摘要如下，點選左下角“閱讀原文”可以自由獲取論文PDF。

Polarization switching of HfO2 ferroelectric in bulk and electrode/ferroelectric/electrode heterostructure

Xinpeng Mu, Yao Wu, Binjian Zeng, Jie Jiang, Yichun Zhou, Lu Yin,*, Min Liao,*, & Qiong Yang,*

HfO2-based ferroelectric films are of great potential for the application of non-volatile information storage. In this paper, to understand the polarization switching properties of ferroelectric HfO2, the 180° polarization switching of HfO2 film in the uniform polarization reversal and domain evolution are studied in both bulk form and Ni/HfO2/Ni heterostructure based on the climbing image nudged elastic band (CI-NEB) simulation. It is found that the polarization reversal pathway with O atoms not shifting through the Hf-atomic planes has higher domain nucleation energy barrier due to the induced high energy domain wall (DW) but lower DW migration energy barrier, which is contrary to the pathway with O atoms shifting through the Hf-atomic planes. However, the interface effect of heterostructure considerably lower the energy barrier for the latter pathway in both uniform polarization reversal and DW migration. This indicates that both types of pathways may be possible and synergistically determine the polarization switching mechanism of HfO2 ferroelectric.