SiTa2: enthalpy of formation
9 accepted literature formation-enthalpy value(s) (experimental 2, model 6, unspecified 1); experimental median -54.043 kJ/mol-atom (n = 2); Materials Project -51.407 kJ/mol-atom (mp-aaaaaedb); OQMD -53.99 kJ/mol-atom (oqmd-7796).
Systems: Si–Ta
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -55.969 kJ/mol-atom | Si0.3333Ta0.6667 | 1027 | experimental | Method unknown | Si–Ta | [1] Drouelle 2013 cites Levine 1969 doi | Table 2, p. 2, row 23 report | |
| -52.117 kJ/mol-atom | Si0.3333Ta0.6667 | 2045 | experimental | Kundsen eff. Method | Si–Ta | [1] Drouelle 2013 cites Myers 1957 doi | Table 2, p. 2, row 21 report | |
| -56 kJ/mol-atom | Ta2Si | model | Si–Ta | [2] Broz 2013 cites Storms 1985 | Table 2, p. 6, row 67 report | |||
| -52.8 kJ/mol-atom | Ta2Si | 0 | model | Si–Ta | [2] Broz 2013 cites Guo 2009 doi | Table 2, p. 6, row 68 report | ||
| -52.1 kJ/mol-atom | Ta2Si | model | Si–Ta | [2] Broz 2013 cites Gorelkin 1971 | Table 2, p. 6, row 65 report | |||
| -52.0086 kJ/mol-atom | Si0.3333Ta0.6667 | 298.15 | model | Optimization | Si–Ta | [1] Drouelle 2013 | Table 2, p. 2, row 22 report | |
| -51 kJ/mol-atom | Si0.3333Ta0.6667 | 298.15 | model | Prediction | Si–Ta | [1] Drouelle 2013 cites F 1988 | Table 2, p. 2, row 20 report | |
| -51 kJ/mol-atom | Ta2Si | model | Si–Ta | [2] Broz 2013 cites Eremenko 1975 | Table 2, p. 6, row 66 report | |||
| -54.3 kJ/mol-atom | Ta2Si | 0 | unspecified | Si–Ta | [2] Broz 2013 | Table 2, p. 6, row 64 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 |
|---|---|---|---|---|---|---|---|---|
| -55.969 | kJ/mol-atom | 5.000e-5 | 4.1 (experimental_unspecified, cleaned_below_threshold) | 4.1 | ||||
| -52.117 | kJ/mol-atom | 5.000e-4 | 4.2 (kems_vapour, calibrated) | 4.2 | ||||
| -56 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -52.8 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -52.1 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -52.0086 | kJ/mol-atom | 5.000e-8 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -51 | kJ/mol-atom | 5.000e-4 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -51 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -54.3 | kJ/mol-atom | 0.05 | 3.5 (unknown, calibrated) | 3.5 |
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-aaaaaedb | -51.407 | -0.532797 | I4/mcm | 0.1556 | 0.0016 | no |
| OQMD | oqmd-7796 | -53.99 | -0.559564 | I4/mcm | 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
- I. Drouelle, C. Servant, Thermodynamic assessment of the Si–Ta system, Journal of Alloys and Compounds 551, 293-299 (2013). doi:10.1016/j.jallcom.2012.09.148
- P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013). doi:10.1016/j.jssc.2012.12.003