CrGa4: enthalpy of formation

8 accepted literature formation-enthalpy value(s) (experimental 3, model 5); experimental median -7.6 kJ/mol-atom (n = 1); Materials Project -15.083 kJ/mol-atom (mp-aaacixqu); OQMD -14.848 kJ/mol-atom (oqmd-29545).

Systems: Cr–Ga

Literature values

Enthalpy of formation of CrGa4 reported in the literature (8)
ValuePhase as printedT (K)ClassMethodSystemSourceLocationQuote
-14.5 kJ/mol (basis unstated) ± 1CrGa4298.15experimentalPrecipitation calorimetryCr–Ga[1] Belgacem-Bouzida 2005Table 4, p. 4, row 17
report
-7.6 kJ/mol (basis unstated)CrGa4298.15experimentalEMFCr–Ga[1] Belgacem-Bouzida 2005
cites Goncharuk 1981
Table 4, p. 4, row 14
report
-7.6 kJ/mol-atomCrGa4850experimentalCr–Ga[2] Gröbner 1999
cites Gonchuruk 1981
Table 1, p. 2, row 50
report
-13.3 kJ/mol (basis unstated)CrGa4modelAssessedCr–Ga[1] Belgacem-Bouzida 2005Table 4, p. 4, row 18
report
-8.7 kJ/mol (basis unstated)CrGa4modelAssessedCr–Ga[1] Belgacem-Bouzida 2005
cites Grobner 1999 doi
Table 4, p. 4, row 15
report
-8.7 kJ/mol-atomCrGa4298.15modelCr–Ga[2] Gröbner 1999Table 1, p. 2, row 51
report
-8 kJ/mol-atomCrGa4298.15modelCr–Ga[2] Gröbner 1999
cites F 1988
Table 1, p. 2, row 52
report
-8 kJ/mol (basis unstated)CrGa4modelSemi-empirical modelCr–Ga[1] Belgacem-Bouzida 2005
cites Djaballah 1999
Table 4, p. 4, row 16
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 CrGa4
ValueUnitPrintedReadingMethod (class, basis)CompositionScatterConversionEffective
-14.5kJ/mol (basis unstated)10.0516 (solution_reaction_calorimetry, calibrated)16
-7.6kJ/mol (basis unstated)0.0523 (emf, cleaned_below_threshold)23
-7.6kJ/mol-atom0.053.5 (unknown, calibrated)3.5
-13.3kJ/mol (basis unstated)0.0519.5 (model_calculated, calibrated)19.5
-8.7kJ/mol (basis unstated)0.0519.5 (model_calculated, calibrated)19.5
-8.7kJ/mol-atom0.053.9 (model_calculated, calibrated)3.9
-8kJ/mol-atom0.53.9 (model_calculated, calibrated)3.9
-8kJ/mol (basis unstated)0.519.5 (model_calculated, calibrated)19.5

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.

DFT formation energy of CrGa4
SourceEntrykJ/mol-atomeV/atomSpace groupE above hull (kJ/mol-atom)E above hull (eV/atom)Theoretical
Materials Projectmp-aaacixqu-15.083-0.156328Im-3m00no
OQMDoqmd-29545-14.848-0.153887Im-3m00no

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. A. Belgacem-Bouzida, Y. Djaballah, M. Notin, Calorimetric measurement of the intermetallic compounds Cr3Ga and CrGa4 and thermodynamic assessment of the (Cr–Ga) system, Journal of Alloys and Compounds 397, 155-160 (2005). doi:10.1016/j.jallcom.2005.01.026
  2. J. Gröbner, R. Wenzel, G. G. Fischer, R. Schmid-Fetzer, Thermodynamic calculation of the binary systems M-Ga and investigation of ternary M-Ga-N phase equilibria (M=Ni, Co, Pd, Cr), JPE 20, 615-625 (1999). doi:10.1361/105497199770340608