Mg24Y5: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (experimental 2, model 1); experimental median -6.815 kJ/mol-atom (n = 2); Materials Project -5.219 kJ/mol-atom (mp-aaaaacym); OQMD -5.806 kJ/mol-atom (oqmd-19035).
Systems: Mg–Y
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -7.53 kJ/mol-atom | Y5Mg24 | 298.15 | experimental | calorimetry | Mg–Y | [1] Fabrichnaya 2003 cites Smith 1965 | Table 4, p. 5, row 12 report | |
| -6.1 kJ/mol-atom | Y5Mg24 | 298.15 | experimental | calorimetry | Mg–Y | [1] Fabrichnaya 2003 cites Pyagai 1990 | Table 4, p. 5, row 13 report | |
| -7.8 kJ/mol-atom | Y5Mg24 | model | Calphad | Mg–Y | [1] Fabrichnaya 2003 | Table 4, p. 5, row 14 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 |
|---|---|---|---|---|---|---|---|---|
| -7.53 | kJ/mol-atom | 0.005 | 3.2 (solution_reaction_calorimetry, calibrated) | 3.2 | ||||
| -6.1 | kJ/mol-atom | 0.05 | 3.2 (solution_reaction_calorimetry, calibrated) | 3.2 | ||||
| -7.8 | 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-aaaaacym | -5.219 | -0.054089 | I-43m | 1.5514 | 0.0161 | no |
| OQMD | oqmd-19035 | -5.806 | -0.060174 | I-43m | 0.2785 | 0.0029 | no |
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
- O.B Fabrichnaya, H.L Lukas, G Effenberg, F Aldinger, Thermodynamic optimization in the Mg–Y system, Intermetallics 11, 1183-1188 (2003). doi:10.1016/s0966-9795(03)00156-0