Hf3Si2: enthalpy of formation
1 accepted literature formation-enthalpy value(s) (experimental 1); experimental median -80 kJ/mol-atom (n = 1); Materials Project -74.298 kJ/mol-atom (mp-aaaaadcz); OQMD -77.301 kJ/mol-atom (oqmd-647083).
Systems: Hf–Si
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -80 kJ/mol-atom ± 4.7 | Hf3Si2 | 1473 | experimental | Hf–Si | [1] Zhao 2000 cites Topor 1990 doi | Table 3, p. 3, row 9 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 |
|---|---|---|---|---|---|---|---|---|
| -80 | kJ/mol-atom | 4.7 | 0.05 | 3.5 (unknown, calibrated) | 4.7 |
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-aaaaadcz | -74.298 | -0.770051 | P4/mbm | 0 | 0 | no |
| OQMD | oqmd-647083 | -77.301 | -0.801176 | P4/mbm | 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
- J. -C. Zhao, B. P. Bewlay, M. R. Jackson, Q. Chen, Hf-Si binary phase diagram determination and thermodynamic modeling, JPE 21, 40-45 (2000). doi:10.1361/105497100770340408