Al2Fe: enthalpy of formation
4 accepted literature formation-enthalpy value(s) (experimental 1, model 2, DFT 1); experimental median -27.8 kJ/mol-atom (n = 1); OQMD -34.734 kJ/mol-atom (oqmd-1376945).
Systems: Al–Fe
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -27.8 kJ/mol-atom ± 1.9 | ζ-Al2Fe | 298.15 | experimental | solution calorimetry | Al–Fe | [1] Ilatovskaia 2023 cites Lukas 2007 | Table 3, p. 6, row 5 report | |
| -23.8 kJ/mol-atom | ζ-Al2Fe | 298.15 | model | Al–Fe | [1] Ilatovskaia 2023 | Table 3, p. 6, row 8 report | ||
| -23.72 kJ/mol-atom | ζ-Al2Fe | 298.15 | model | Al–Fe | [1] Ilatovskaia 2023 cites Zienert 2018 doi | Table 3, p. 6, row 7 report | ||
| -124.42 kJ/mol (basis unstated) | FeAl2 | DFT | DFT | Al–Fe | [2] Ostrowska 2019 cites AFLOW | Table 3, p. 3, row 3 report |
Uncertainty budget
Components kept separate, in the value's unit (literature SCHEMA.md, UNCERTAINTY_CALIBRATION.md): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.
| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---|---|---|---|---|---|---|---|---|
| -27.8 | kJ/mol-atom | 1.9 | 0.05 | 3.2 (solution_reaction_calorimetry, calibrated) | 3.2 | |||
| -23.8 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -23.72 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -124.42 | kJ/mol (basis unstated) | 0.005 | 11.79 (dft, calibrated) | 11.79 |
DFT formation energies
Lowest-energy entries at this composition. Materials Project and OQMD use different energy references and are never averaged. 1 eV/atom = 96.485 kJ/mol-atom.
| Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical |
|---|---|---|---|---|---|---|---|
| OQMD | oqmd-1376945 | -34.734 | -0.359989 | I4/mmm | 0 | 0 | yes |
DFT sources: A. Jain et al., Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002. doi:10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501-1509; S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010. doi:10.1007/s11837-013-0755-4 (CC BY 4.0);
Sources
- M. Ilatovskaia, H. Becker, O. Fabrichnaya, A. Leineweber, The η-Al5Fe2 phase in the Al–Fe system: The issue with the sublattice model, Journal of Alloys and Compounds 936, 168361 (2023). doi:10.1016/j.jallcom.2022.168361
- Marlena Ostrowska, Gabriele Cacciamani, Critical evaluation and thermodynamic modeling of the Al-Co-Fe system, Journal of Alloys and Compounds 794, 553-568 (2019). doi:10.1016/j.jallcom.2019.04.170