ScSi: enthalpy of formation

5 accepted literature formation-enthalpy value(s) (experimental 3, model 2); experimental median -87.21 kJ/mol-atom (n = 3); Materials Project -77.326 kJ/mol-atom (mp-aaaaaotl); OQMD -80.839 kJ/mol-atom (oqmd-7936).

Systems: Sc–Si

Literature values

Enthalpy of formation of ScSi reported in the literature (5)
ValuePhase as printedT (K)ClassMethodSystemSourceLocationQuote
-117.2 kJ/mol-atomScSi298.15experimentalAcid solution calorimetrySc–Si[1] Qin 2015
cites Golutvin 1984
Table 2, p. 3, row 1
report
-87.21 kJ/mol-atom ± 2.1ScSi935experimentalEMFSc–Si[1] Qin 2015
cites Lukashenko 1992 doi
Table 2, p. 3, row 3
report
-82.3 kJ/mol-atom ± 2.1ScSi298.15experimentalHigh temperature synthesis calorimetrySc–Si[1] Qin 2015
cites Meschel 1998 doi
Table 2, p. 3, row 4
report
-81.2 kJ/mol-atomScSi298.15modelCalculatedSc–Si[1] Qin 2015Table 2, p. 3, row 7
report
-80 kJ/mol-atomScSi0modelPredictedSc–Si[1] Qin 2015
cites Niessen 1981
Table 2, p. 3, row 5
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.

Uncertainty budget of the literature values of ScSi
ValueUnitPrintedReadingMethod (class, basis)CompositionScatterConversionEffective
-117.2kJ/mol-atom0.053.2 (solution_reaction_calorimetry, calibrated)3.2
-87.21kJ/mol-atom2.10.0054.6 (emf, cleaned_below_threshold)4.6
-82.3kJ/mol-atom2.10.053.2 (solution_reaction_calorimetry, calibrated)3.2
-81.2kJ/mol-atom0.053.9 (model_calculated, calibrated)3.9
-80kJ/mol-atom0.053.9 (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.

DFT formation energy of ScSi
SourceEntrykJ/mol-atomeV/atomSpace groupE above hull (kJ/mol-atom)E above hull (eV/atom)Theoretical
Materials Projectmp-aaaaaotl-77.326-0.80143Cmcm00no
OQMDoqmd-7936-80.839-0.837843Cmcm00no

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

  1. Aning Qin, Dandan Liu, Chong Chen, Shuhong Liu, Yong Du, Man Wang et al., Heat contents of Sc5Si3 and ScSi intermetallics and thermodynamic modeling of the Sc–Si system, J Therm Anal Calorim 119, 1315-1321 (2015). doi:10.1007/s10973-014-4216-2