GeY: enthalpy of formation
4 accepted literature formation-enthalpy value(s) (experimental 1, model 3); experimental median -98 kJ/mol-atom (n = 1); Materials Project -86.308 kJ/mol-atom (mp-aaaaaotn); OQMD -86.397 kJ/mol-atom (oqmd-7938).
Systems: Ge–Y
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -98 kJ/mol-atom ± 4.9 | GeY | 870 | experimental | EMF | Ge–Y | [1] Idbenali 2013 cites Polotskaya 1996 doi | Table 4, p. 5, row 10 report | |
| -108.8 kJ/mol-atom | GeY | model | Calculation | Ge–Y | [1] Idbenali 2013 cites Miedema 1976 doi | Table 4, p. 5, row 24 report | ||
| -101.53 kJ/mol-atom | GeY | 298.15 | model | Optimization | Ge–Y | [1] Idbenali 2013 | Table 4, p. 5, row 13 report | |
| -86.218 kJ/mol-atom | GeY | 870 | model | Optimization | Ge–Y | [1] Idbenali 2013 | Table 4, p. 5, row 12 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 |
|---|---|---|---|---|---|---|---|---|
| -98 | kJ/mol-atom | 4.9 | 0.5 | 4.6 (emf, cleaned_below_threshold) | 4.9 | |||
| -108.8 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -101.53 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -86.218 | kJ/mol-atom | 5.000e-4 | 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-aaaaaotn | -86.308 | -0.894524 | Cmcm | 0 | 0 | no |
| OQMD | oqmd-7938 | -86.397 | -0.895447 | Cmcm | 0 | 0 | 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
- Mohamed Idbenali, Colette Servant, Thermodynamic optimization of the germanium–yttrium system, J Therm Anal Calorim 111, 911-916 (2013). doi:10.1007/s10973-012-2271-0