无和热力学重新定义了铁电HfO中的元稳定性和母相2
Yiheng Shen1, Chang Liu2, Wei Xie1
1Materials Genome Institute, Shanghai University, Shanghai 200444, China.
The journal of physical chemistry letters
|March 17, 2026
概括
稳定铁电的哈夫尼亚 (HfO2) 是很困难的. 这项研究揭示了铁电相在低于先前想象的温度下具有转移稳定性,这突显了HfO2材料设计中不和性的重要性.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 计算材料科学科学 计算材料科学
背景情况:
- 哈夫尼亚 (HfO2) 是用于铁电应用的有前途的兼容介电体.
- 稳定HfO2所需的铁电相是一个重大挑战.
- 之前的相稳定性预测依赖于密度函数理论 (DFT) 与波近似,经常忽视非波效应.
研究的目的:
- 为了研究 ferroelectric Hafnia (HfO2) 的相稳定性,考虑一个harmonicity.
- 开发一种机器学习力场,用于对HfO2.2进行精确的热力学计算.
- 为设计稳定的基于HfO2的铁电材料提供指导.
主要方法:
- 为HfO2.2开发机器学习力场的开发.
- 使用自相一致的声理论进行热力学计算.
- 模拟涵盖了6001500 K的温度范围和高达7.5 GPa的压力.
主要成果:
- 在模拟条件下,HfO2的铁电直相 (oIII) 在0.1kB*T以下表现出转移稳定性.
- 这与之前的波预测相矛盾,这些预测表明在1500K以上的环境压力下具有转移稳定性.
- 观察到温度和压力依赖的铁电母相的证据.
结论:
- 无声效应对于准确预测Hfnia (HfO2) 的相稳定性至关重要.
- HfO2的铁电相在低于此前估计的温度下是不稳定的.
- 开发的方法为设计基于HfO2的铁电材料提供了一种有效的方法.
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