ErGe: enthalpy of formation

3 accepted literature formation-enthalpy value(s) (experimental 1, model 2); experimental median -92.2 kJ/mol-atom (n = 1); Materials Project -82.273 kJ/mol-atom (mp-aaaaadjc); OQMD -82.483 kJ/mol-atom (oqmd-7744).

Systems: Er–Ge

Literature values

Enthalpy of formation of ErGe reported in the literature (3)
ValuePhase as printedT (K)ClassMethodSystemSourceLocationQuote
-92.2 kJ/mol-atom ± 1.8ErGe950experimentalEMFEr–Ge[1] Achgar 2017
cites Sidorko 2008
Table 5, p. 7, row 13
report
-94.15 kJ/mol-atomErGe950modelOptimizationEr–Ge[1] Achgar 2017Table 5, p. 7, row 15
report
-93.66 kJ/mol-atomErGe950modelOptimizationEr–Ge[1] Achgar 2017Table 5, p. 7, row 14
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 ErGe
ValueUnitPrintedReadingMethod (class, basis)CompositionScatterConversionEffective
-92.2kJ/mol-atom1.80.054.6 (emf, cleaned_below_threshold)4.6
-94.15kJ/mol-atom0.0053.9 (model_calculated, calibrated)3.9
-93.66kJ/mol-atom0.0053.9 (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 ErGe
SourceEntrykJ/mol-atomeV/atomSpace groupE above hull (kJ/mol-atom)E above hull (eV/atom)Theoretical
Materials Projectmp-aaaaadjc-82.273-0.852698Cmcm00no
OQMDoqmd-7744-82.483-0.85488Cmcm00no

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. Khadija Achgar, Saïd Kardellass, Najim Selhaoui, Lahcen Bouirden, Thermodynamic optimization of the Erbium-Germanium binary system, Journal of Alloys and Compounds 724, 1157-1166 (2017). doi:10.1016/j.jallcom.2017.07.129