AlY: enthalpy of formation
2 accepted literature formation-enthalpy value(s) (experimental 1, model 1); experimental median -87.8 kJ/mol-atom (n = 1); Materials Project -40.364 kJ/mol-atom (mp-aaaaaqpw); OQMD -42.255 kJ/mol-atom (oqmd-1782622).
Systems: Al–Y
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -87.8 kJ/mol-atom | YAl | 298.15 | experimental | Combustion calorimetry | Al–Y | [1] Gröbner 1995 cites Snyder 1960 | Table 1, p. 2, row 5 report | |
| -45 kJ/mol-atom | YAl | model | Al–Y | [1] Gröbner 1995 | Table 1, p. 2, row 6 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 |
|---|---|---|---|---|---|---|---|---|
| -87.8 | kJ/mol-atom | 0.05 | 1 (combustion_calorimetry, cleaned_below_threshold) | 1 | ||||
| -45 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 |
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 |
|---|---|---|---|---|---|---|---|
| Materials Project | mp-aaaaaqpw | -40.364 | -0.418347 | Cmcm | 0.4508 | 0.0047 | no |
| OQMD | oqmd-1782622 | -42.255 | -0.437948 | Pbcm | 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
- J. Gröbner, H.-L. Lukas, F. Aldinger, Thermodynamic calculations in the YAlC system, Journal of Alloys and Compounds 220, 8-14 (1995). doi:10.1016/0925-8388(94)06028-2