About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Computational Thermodynamics and Kinetics
|
| Presentation Title |
Chemical Potentials Are Not Free Parameters: A Thermodynamic Framework for Point Defect Calculations |
| Author(s) |
Wolfgang Windl |
| On-Site Speaker (Planned) |
Wolfgang Windl |
| Abstract Scope |
Chemical potentials play a central role in point-defect calculations, yet their physical meaning and permissible ranges in non-elemental solids are often misunderstood. Atomic chemical potentials are frequently explored only at elemental end-member limits, while the electronic chemical potential (Fermi level) in non-metals is commonly treated as an arbitrary variable spanning the band gap. Here, I propose thermodynamically sensible bounds for chemical potentials and demonstrate that they are uniquely determined by the material’s stoichiometry. In gapped materials, I show that the Fermi level is fully determined by stoichiometry and extrinsic doping. I will demonstrate the proposed approach for alloy, intermetallic, and compound semiconductor examples and show that the results are consistent with experiments. One especially exciting outcome of this framework is that it enables prediction of whether an intermetallic exhibits line-compound behavior or finite homogeneity ranges based solely on the stability limits of point defects, without recourse to other thermodynamic modeling. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, Other |