• DOI:10.1103/PhysRevB.105.064104
• Corpus ID: 246036073

Structural Phase Transitions in SrTiO3 from Deep Potential Molecular Dynamics

@inproceedings{He2022StructuralPT,
  title={Structural Phase Transitions in SrTiO3 from Deep Potential Molecular Dynamics},
  author={Ri He and Hongyu Wu and Linfeng Zhang and Xiaoxu Wang and Fangjia Fu and Shih-Hao Liu and Zhicheng Zhong},
  year={2022}
}

• R. He, Hongyu Wu, +4 authors Z. Zhong
• Published 18 January 2022
• Materials Science

Strontium titanate (SrTiO3) is regarded as an essential material for oxide electronics. One of its many remarkable features is subtle structural phase transition, driven by antiferrodistortive lattice mode, from a high-temperature cubic phase to a lowtemperature 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 SrTiO3 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 temperaturedriven cubic-to-tetragonal phase transition and construct the in-plane biaxial straintemperature phase diagram of SrTiO3. The simulations demonstrate that strain-induced ferroelectric phase is characterized by two order parameters, ferroelectric distortion and antiferrodistortion, and the ferroelectric phase transition has both displacive and order# These authors contribute equally to this work * [e-mail] * [e-mail] disorder characters. This works lays the foundation for the development of accurate DP models of other complex perovskite materials.