About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Computational Thermodynamics and Kinetics
|
| Presentation Title |
Defect Energy Formalism for CALPHAD Thermodynamics of Dilute Point Defects |
| Author(s) |
Amir Mohammad Orvati Movaffagh, Sara Kadkhodaei |
| On-Site Speaker (Planned) |
Amir Mohammad Orvati Movaffagh |
| Abstract Scope |
This work introduces the Defect Energy Formalism (DEF) within the CALPHAD framework—a fully first-principles approach for studying dilute point defects that eliminates the need for fitting to experimental or simulation data. We first present the theoretical derivation of DEF, which establishes explicit relationships between defect energies and the Gibbs energy of defective compounds. Notably, DEF enables the use of published DFT data on defect energetics, which is then calibrated using a standard procedure to reconcile differences in energy reference conventions between DFT and CALPHAD-based models and serve as the primary input to DEF. Given that thermochemical characterization of defects is resource-intensive, DEF offers a streamlined alternative based on ab initio data and rigorous thermodynamic principles. To illustrate the full modeling workflow, we apply DEF to point defects in magnesium silicide and demonstrate how layers of complexity—such as entropy contributions—and their interplay influence the resulting defect concentrations. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, Other |