About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
AI/Data Informatics: Computational Model Development, Validation, and Uncertainty Quantification
|
Presentation Title |
Modelling Nucleation in Crystal Phase Transition from Machine Learning Metadynamics |
Author(s) |
Qiang Zhu, Pedro Santos-Florez, Howard Yanxon, Yansun Yao |
On-Site Speaker (Planned) |
Qiang Zhu |
Abstract Scope |
In this work, we present an efficient framework that combines machine learning potential (MLP) and metadynamics to investigate solid-solid phase transition. We have developed a scalable MLP model to warrant an accurate interpolation of the energy surface where two phases coexist. Applying the framework to the metadynamics simulation of B4-B1 phase transition of GaN under 50 GPa with different model sizes, we observe the sequential change of phase transition mechanism from collective modes to nucleation and growths. With a small size, the nucleation and growth appear to follow a preferred direction. At larger sizes, the nucleation tends to occur at multiple sites simultaneously and grow to microstructures by passing the critical size. The observed change of atomistic mechanism manifests the importance of statistical sampling with large system size. The combination of MLP and metadynamics is likely to be applicable to a broad class of reconstructive phase transitions at extreme conditions. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Machine Learning, Phase Transformations |