About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
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Symposium
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Bridging Scale Gaps in Multiscale Materials Modeling in the Age of Artificial Intelligence
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Presentation Title |
Pathways to the 7 × 7 Surface Reconstruction of Si(111) Revealed by Machine-Learning Molecular Dynamics Simulations |
Author(s) |
Yidi Shen, Kun Luo, William A Goddard, Qi An |
On-Site Speaker (Planned) |
Qi An |
Abstract Scope |
The well-known 7 × 7 structure of the Si(111) surface, formed upon annealing, has long puzzled researchers due to its complex reconstruction mechanism. We employ molecular dynamics simulations enhanced by a machine-learning force field for silicon to explore the formation of the Si(111)-7 × 7 surface reconstruction from the melt. Our simulations reveal two potential pathways: the growth of a faulted half domain transitioning from a metastable 5 × 5 phase to the final 7 × 7 configuration, and the direct formation of the 7 × 7 structure. Both pathways involve the creation of dimers and bridged five-membered rings, followed by the stabilization of triangular halves within the unit cell. The distinctive corner hole forms through the aggregation of multiple five-member rings. Additionally, atom insertion beneath adatoms to establish a dumbbell configuration requires extra diffusion or rearrangement. Our results provide valuable insights into surface reconstruction in semiconductors. |
Proceedings Inclusion? |
Planned: |
Keywords |
Machine Learning, Surface Modification and Coatings, Thin Films and Interfaces |