Si4Y5: enthalpy of formation
5 accepted literature formation-enthalpy value(s) (experimental 1, model 3, DFT 1); experimental median -93 kJ/mol-atom (n = 1); Materials Project -71.399 kJ/mol-atom (mp-aaacqgzq); OQMD -74.682 kJ/mol-atom (oqmd-643385).
Systems: Si–Y
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -93 kJ/mol-atom ± 5.5 | Y5Si4 | 850.15 | experimental | Si–Y | [1] Xu 2019 cites Polotskaya 1997 doi | Table 2, p. 3, row 15 report | ||
| -81.222 kJ/mol-atom | Y5Si4 | model | Si–Y | [1] Xu 2019 cites Shukla 2009 doi | Table 2, p. 3, row 16 report | |||
| -76.67 kJ/mol-atom | Y5Si4 | model | CALPHAD | Si–Y | [1] Xu 2019 | Table 3, p. 3, row 4 report | ||
| -65.15 kJ/mol-atom | Y5Si4 | model | Si–Y | [1] Xu 2019 cites Ran 1989 | Table 2, p. 3, row 17 report | |||
| -75.09 kJ/mol-atom | Y5Si4 | 0 | DFT | First principles | Si–Y | [1] Xu 2019 | 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 |
|---|---|---|---|---|---|---|---|---|
| -93 | kJ/mol-atom | 5.5 | 0.05 | 3.5 (unknown, calibrated) | 5.5 | |||
| -81.222 | kJ/mol-atom | 5.000e-4 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -76.67 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -65.15 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -75.09 | kJ/mol-atom | 0.005 | 9.966 (dft, calibrated) | 9.966 |
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-aaacqgzq | -71.399 | -0.740002 | Pnma | 2.1108 | 0.0219 | no |
| OQMD | oqmd-643385 | -74.682 | -0.774025 | P21/c | 1.964 | 0.0204 | 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
- Kai Xu, Houke Zou, Keke Chang, Zixuan Deng, Xiaobing Zhou, Yeyan Huang et al., Thermodynamic description of the sintering aid system in silicon carbide ceramics with the addition of yttrium, Journal of the European Ceramic Society 39, 4510-4519 (2019). doi:10.1016/j.jeurceramsoc.2019.07.012