来自深势分子动力学的 SrTiO3 结构相变,Physical Review B

当前位置： X-MOL 学术 › Phys. Rev. B › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

来自深势分子动力学的 SrTiO3 结构相变
Physical Review B ( IF 3.2 ) Pub Date : 2022-02-15 , DOI: 10.1103/physrevb.105.064104
Ri He ₁ , Hongyu Wu ₁ , Linfeng Zhang _{2,

3} , Xiaoxu Wang _{2,

3} , Fangjia Fu _{3,

4} , Shi Liu _{5,

6,

7} , Zhicheng Zhong _{1,

8}

Affiliation

钛酸锶 (

锶钛 ○_{3}

) 被认为是氧化物电子学的基本材料。它的许多显着特征之一是由反铁扭曲晶格模式驱动的从高温立方相到低温四方相的微妙结构相变。经典分子动力学 (MD) 模拟是揭示相变原子特征的有效技术，但其应用通常受到经验原子间势的准确性的限制。在这里，我们开发了一个准确的深电位（DP）模型

锶钛 ○_{3}

基于使用来自第一性原理密度泛函理论 (DFT) 计算的数据的机器学习方法。DP 模型具有 DFT 级别的精度，能够执行高效的 MD 模拟和准确的属性预测。使用DP模型，我们研究了温度驱动的立方到四方相变并构建了面内双轴应变-温度相图

锶钛 ○_{3}

. 模拟表明，应变诱导铁电（FE）相具有两个有序参数，FE畸变和反铁电畸变，并且FE相变具有位移和有序无序特征。在本文中，我们为开发其他复杂钙钛矿材料的精确 DP 模型奠定了基础。

"点击查看英文标题和摘要"

Structural phase transitions inSrTiO3from deep potential molecular dynamics

Strontium titanate (

SrTi O_{3}

) is regarded as an essential material for oxide electronics. One of its many remarkable features is the subtle structural phase transition, driven by the antiferrodistortive lattice mode, from a high-temperature cubic phase to a low-temperature tetragonal phase. Classical molecular dynamics (MD) simulation is an efficient technique to reveal atomistic features of phase transition, but its application is often limited by the accuracy of empirical interatomic potentials. Here, we develop an accurate deep potential (DP) model of

SrTi O_{3}

based on a machine learning method using data from first-principles density functional theory (DFT) calculations. The DP model has DFT-level accuracy, capable of performing efficient MD simulations and accurate property predictions. Using the DP model, we investigate the temperature-driven cubic-to-tetragonal phase transition and construct the in-plane biaxial strain-temperature phase diagram of

SrTi O_{3}

. The simulations demonstrate that the strain-induced ferroelectric (FE) phase is characterized by two order parameters, FE distortion and antiferrodistortion, and the FE phase transition has both displacive and order-disorder characters. In this paper, we lay the foundation for the development of accurate DP models of other complex perovskite materials.

更新日期：2022-02-15

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南