About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Photomechanical and Electromechanical Effects in Structural and Functional Materials
|
| Presentation Title |
First-Principles Insight into Anomalous Electroplasticity in ZnS |
| Author(s) |
Takahiro Shimada, Susumu Minami, Kohta Kasai, Yu Zou |
| On-Site Speaker (Planned) |
Takahiro Shimada |
| Abstract Scope |
Anomalous electroplasticity, in which dislocations move under an applied electric field without mechanical loading, has recently been observed experimentally in ZnS. Understanding its microscopic mechanism is essential for electrically controlling dislocation-mediated functionalities and defect engineering. Here, we investigate the atomistic origin of electric-field-induced dislocation motion in ZnS using first-principles finite-electric-field density functional theory calculations. A dipole model containing two 30-degree partial dislocations in zinc-blende ZnS was analyzed with spin-polarized DFT. The calculations reveal that partial dislocations can glide solely under an applied electric field. Nudged Elastic Band calculations further show that dislocation motion proceeds through a two-step process involving two activation barriers. The applied electric field systematically lowers the forward migration barriers while increasing the reverse barriers, thereby promoting directional dislocation motion. Incorporating these field-dependent barriers into an Arrhenius framework yields dislocation velocities in good agreement with experimental observations, providing an atomistic explanation for the anomalous electroplastic phenomenon in ZnS. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Mechanical Properties, Ceramics |